Electro-optical device

ABSTRACT

An electro-optical device includes a TFT, a data line, a scanning line, and a pixel electrode, which are provided above a substrate, a semiconductor layer which constitutes the TFT being connected to the pixel electrode through a relay film. A light-shielding conductive film provided between the data line and the relay film is electrically connected to a capacitor electrode which consists of the same film as the scanning line provided between the relay film and the semiconductor layer at a constant potential, thereby forming a storage capacitor between the films. Therefore, in an electro-optical device of a type in which a light-shielding film against incident light is provided above pixel switching TFT, and a light-shielding film against returned light is provided below the TFT, the pixel aperture ratio can be increased, and the storage capacitor can be enlarged.

[0001] This is a Divisional of co-pending application Ser. No.09/809,275, filed Mar. 16, 2001, now allowed.

BACKGROUND OF THE INVENTION

[0002] 1. Field of Invention

[0003] The present invention relates to the technical field of an activematrix driving system electro-optical device. Particularly, the presentinvention relates to the technical field of an electro-optical devicewhich includes a pixel electrode and a pixel switching thin filmtransistor (referred to as “TFT” hereinafter), which are provided withelectrical conduction therebetween, and a storage capacitor and alight-shielding film which are provided in a laminated structure formedon a substrate.

[0004] 2. Description of Related Art

[0005] In a conventional electro-optical device such as a TFT-drivenactive matrix driving system liquid crystal device, a scanning signal issupplied to a gate electrode of a TFT through a scanning line to turnthe TFT on, and an image signal supplied to a source region of asemiconductor layer through a data line is supplied to a pixel electrodethrough the region between the source and drain of the TFT. Such animage signal is supplied to each of a plurality of pixel electrodes foronly a short time through each of a plurality of TFTs. Therefore, inorder to hold the voltage of the image signal supplied through a TFTover a longer time than the time of the on state, a storage capacitor isgenerally added to each pixel electrode.

[0006] When light is incident on at least a portion of a channel regionor junction regions between the channel region and source-drain regions,and the source-drain regions adjacent to the junction regions in asemiconductor layer which constitutes the TFT, light excitation occursto change the transistor properties of the TFT, for example, increase aleakage current in the on state. Therefore, for example, in anelectro-optical device of a type in which strong light is incident, suchas a transmissive electro-optical device for a projector, in order toprevent such a change in the properties of the TFT with light incidence,a light-shielding film is provided on a counter substrate on theincidence side of incident light to cover the space between the pixelelectrodes including the channel region of the TFT, or an opaque widedata line which includes an Al film or the like is formed to cover thechannel region. Furthermore, on the outgoing side, a light-shieldingfilm is provided below the TFT to shield light reflected by the back,and returned light such as incident light from another electro-opticaldevice, which passes through a synthesis optical system, in a projectorthat includes a combination of a plurality of electro-optical devices.

SUMMARY OF THE INVENTION

[0007] In this type of electro-optical device, improvement in quality ofa display image is strongly demanded, and in order to satisfy thisdemand, it is important that a pixel aperture region of each pixelthrough which display light is transmitted is widened relative to anon-pixel aperture region through which display light is nottransmitted, to increase the pixel aperture ratio while decreasing thepixel pitch, and enlarge a storage capacitor added to each pixelelectrode.

[0008] The storage capacitor is generally formed by utilizing thenon-pixel aperture region, and it is thus basically difficult to formthe storage capacitor in the pixel aperture region. Therefore, thenon-pixel aperture region where the storage capacitor can be formed isnarrowed as the pixel aperture region is widened to increase the pixelaperture ratio. However, there is a problem in which the pixel apertureratio is decreased as the non-pixel aperture region is widened toenlarge the storage capacitor.

[0009] It is also very important to sufficiently shield incident lightand reflected light in a channel region of TFT or a region (referred toas the “adjacent region of channel” hereinafter) adjacent to the channelregion, for example, a lightly-doped region of LDD structure TFT, asdescribed above. Namely, a decrease in the pixel pitch causessignificant deterioration in image quality resulting from only a slightchange in properties of TFT.

[0010] However, a total plane region where a light-shielding film or afilm having a light shielding function can be arranged is narrowed byincreasing the pixel aperture ratio, thereby causing the problem ofcausing difficulties in completely shielding TFT from light.Furthermore, a decrease in the pixel pitch causes a problem in whicheven with incident light or reflected light slightly inclined with thesubstrate surface, light finally enters the channel region or theadjacent region of channel due to the occurrence of multiple reflectionin a laminated structure after oblique incidence. Particularly, when theincidence side is covered with a data line which includes an Al filmhaving high reflectance, shielding against incident light approachesperfection with widening of the data line, but widening the data lineconversely causes a problem difficult to resolve in which reflectedlight is reflected by the side facing TFT or subsequently reflected bythe TFT-facing surface of a light-shielding film formed below TFT, andthe light is likely to be finally incident on the channel region or theadjacent region of channel. Furthermore, shielding against reflectedlight approaches perfection with widening of the light-shielding filmformed below TFT, but widening the light-shielding film formed below TFTcauses a problem difficult to resolve in which oblique incident light isreflected by the inner surface of the light-shielding film, orsubsequently reflected by the inner surfaces of the data line, and islikely to be finally incident on the channel region or the adjacentregion of channel. Particularly, in an electro-optical device for aprojector which uses incident light or reflected light having very highintensity per unit region, the above problems are very important forimproving image quality.

[0011] The present invention has been achieved at least in considerationof the above problems, and an object of the present invention is toprovide an electro-optical device in which a pixel aperture ratio can beincreased, a storage capacitor can be enlarged, and a high quality imagecan be displayed.

[0012] Another object of the present invention is to provide anelectro-optical device in which a change in properties of pixelswitching TFT due to incident light or reflected light can be decreasedwhile increasing the pixel aperture ratio, and a high quality image canbe displayed.

[0013] (1) In a first exemplary aspect of the present invention, anelectro-optical device may include a scanning line formed above asubstrate, a data line crossing the scanning line, a thin filmtransistor connected to the scanning line and the data line, a pixelelectrode connected to a drain region of the thin film transistor, and afirst storage capacitor formed by a plurality of layers between thescanning line and the data line.

[0014] In this exemplary embodiment of the present invention, the firststorage capacitor is formed by a plurality of layers between thescanning line and the data line by utilizing the laminated structure toenlarge the storage capacitor, thereby providing an electro-opticaldevice capable of displaying a high quality image.

[0015] (2) In another exemplary embodiment of the first aspect of theinvention, in the electro-optical device, the first storage capacitormay include a first capacitor electrode, an insulating film facing thefirst capacitor electrode, and a second capacitor electrode opposed tothe first capacitor electrode with the insulating film providedtherebetween to serve as a relay film for electrically connecting adrain region of the thin film transistor and the pixel electrode.

[0016] In this exemplary embodiment of the present invention, the secondcapacitor electrode which forms the first storage capacitor is formed asthe relay film for electrically connecting the drain region of the thinfilm transistor and the pixel electrode, whereby the problem of causinga difficulty in electrically connecting the pixel electrode and asemiconductor layer due to a long distance therebetween can be solved.Also, the second capacitor electrode can prevent etching penetrationduring the formation of a contact hole.

[0017] (3) In still another exemplary embodiment of the first aspect ofthe present invention, in the electro-optical device, the first storagecapacitor is formed to overlap with each of the semiconductor layers ofthe thin film transistor and the scanning line, except the connectionregion between the source region of the thin film transistors and thedata line.

[0018] In this exemplary embodiment of the present invention, since thestorage capacitor is formed to overlap with each of the semiconductorlayers and the scanning line, it is possible to increase the pixelaperture ratio, and to enlarge the storage capacitor.

[0019] (4) In a further exemplary embodiment of the first aspect of thepresent invention, the electro-optical device may further include asecond storage capacitor which may include a second capacitor electrode,an insulating film facing the second capacitor electrode, and a thirdcapacitor electrode opposed to the second capacitor electrode with theinsulating film provided therebetween and consisting of the same film asthe scanning line.

[0020] In this exemplary embodiment of the present invention, since thesecond storage capacitor is formed by using the second capacitorelectrode, which forms the first storage capacitor, and the scanningline layer, storage capacitors can be laminated in the thicknessdirection of the substrate, and even with narrow pixel pitch, arelatively large storage capacitor can be formed in a non-apertureregion. In addition, the third capacitor electrode may include the samefilm as the scanning line, storage capacitors can thus be formed by alaminated structure which may consist of a relatively small number oflayers.

[0021] (5) In a still further exemplary embodiment of the first aspectof the present invention, in the electro-optical device, the thirdcapacitor electrode is formed in parallel with the scanning line exceptin the connection region between the drain region of the thin filmtransistor and the second capacitor electrode.

[0022] In this exemplary embodiment of the present invention, since thethird capacitor electrode is formed in parallel with the scanning line,a storage capacitor can be formed by utilizing the non-aperture region.

[0023] (6) In a further exemplary embodiment of the first aspect of thepresent invention, in the electro-optical device, the third capacitorelectrode is electrically connected to the first capacitor electrode.

[0024] In this exemplary embodiment of the present invention, nopotential variation occurs between the first capacitor electrode and thethird capacitor electrode, whereby the possibility of affecting theproperties of the thin film transistors can be prevented.

[0025] (7) In a further exemplary embodiment of the first aspect of thepresent invention, in the electro-optical device, the electricalconnection between the third capacitor electrode and the first capacitorelectrode is located in a region below the data line.

[0026] In this exemplary embodiment of the present invention, the spacebetween the pixel electrodes, which are located below the data line andwhich cannot be used as an aperture region for each pixel, is used forconnecting the third capacitor electrode and the first capacitorelectrode, thereby causing an advantage for improving the pixel apertureratio.

[0027] (8) In a further exemplary embodiment of the first aspect of thepresent invention, in the electro-optical device, the third capacitorelectrode may include a part of a first capacitor line extending alongthe scanning line, the first capacitor electrode may include a part of asecond capacitor line extending along the scanning line, and the firstand second capacitor lines are extended to the periphery of the imagedisplay region in which the pixel electrode is arranged, andelectrically connected to each other.

[0028] In this exemplary embodiment of the present invention, the firstcapacitor line arranged along the scanning line and including aplurality of third capacitor electrodes, and the second capacitor linearranged along the scanning line and including a plurality of firstcapacitor electrodes are electrically connected to each other outsidethe image display region to permit relatively simple and secureelectrical connection between the third capacitor electrodes and thefirst capacitor electrodes through the first and second capacitor lines.Also, contact holes need not be provided for connecting both capacitorelectrodes in the image display region, and thus the storage capacitorscan be enlarged.

[0029] (9) In a further exemplary embodiment of the first aspect of thepresent invention, the electro-optical device may further include athird storage capacitor comprising the third capacitor electrode, aninsulating film facing the third capacitor electrode, and a fourthcapacitor electrode opposed to the third capacitor electrode with theinsulating films provided therebetween and which may consist of the samefilm as the semiconductor layer.

[0030] In this exemplary embodiment of the present invention, the thirdstorage capacitor is formed by using the third capacitor electrode,which constitutes the second storage capacitor, and the semiconductorlayer, and storage capacitors can thus be laminated in the thicknessdirection of the substrate, thereby permitting the construction of arelatively large storage capacitor in the non-aperture region, even whenthe pixel pitch is decreased. Also, the fourth capacitor electrode mayinclude the same film as the semiconductor layer, and thus storagecapacitors can be constructed by a laminated structure which may includea relatively small number of layers.

[0031] (10) In a further exemplary embodiment of the first aspect of thepresent invention, in the electro-optical device, the fourth capacitorelectrode is formed to extend from the drain region of the thin filmtransistor.

[0032] In this exemplary embodiment of the present invention, a storagecapacitor can be formed by using the drain region of the thin filmtransistor.

[0033] (11) In a further exemplary embodiment of the first aspect of thepresent invention, in the electro-optical device, the fourth capacitorelectrode is formed in parallel with the scanning line.

[0034] In this exemplary embodiment of the present invention, the thirdcapacitor electrode is formed in parallel with the scanning line, andthus storage capacitors can be enlarged by using the non-apertureregion.

[0035] (12) In a further exemplary embodiment of the first aspect of thepresent invention, in the electro-optical device, the capacitance of thesecond storage capacitor is smaller than that of each of the firststorage capacitor and the third storage capacitor.

[0036] In this exemplary embodiment of the present invention, the secondstorage capacitor which includes the first capacitor electrode and thethird capacitor electrode consisting of the same film as the scanningline is small, and thus capacitors can be formed without affecting errorin the operation of the TFT.

[0037] (13) In a further exemplary embodiment of the first aspect of thepresent invention, the electro-optical device may further include afourth storage capacitor which may include the fourth capacitorelectrode consisting of the same film as the semiconductor layer, aninsulating film facing the fourth capacitor electrode, and a fifthcapacitor electrode arranged opposite to the fourth capacitor electrodewith the insulating film provided therebetween, for shielding thesemiconductor layer from light.

[0038] In this exemplary embodiment of the present invention, the fourthstorage capacitor is formed by using the fourth capacitor electrodeconsisting of the same film as the semiconductor layer, whichconstitutes the third storage capacitor, and a light-shielding film forshielding the semiconductor layer from light, and storage capacitors canthus be laminated in the thickness direction of the substrate, therebypermitting the construction of a relatively large storage capacitor inthe non-aperture region even when the pixel pitch is decreased. Also,the fifth capacitor electrode may include the light-shielding film, andthus storage capacitors can be constructed by a laminated structurewhich may include a relatively small number of layers. In addition, thelight-shielding film is formed to cover the substrate side of at leastthe channel region, whereby the properties of the thin film transistorscan be effectively prevented from being changed by incidence of thereturned light from the substrate side on the channel region.

[0039] (14) In a further exemplary embodiment of the first aspect of thepresent invention, in the electro-optical device, the fifth capacitorelectrode is electrically connected to the first capacitor electrode inthe periphery of the image display region.

[0040] In this construction of the present invention, the firstcapacitor electrode, the fifth capacitor electrode and the thirdcapacitor electrode can be formed with a common potential, therebypermitting the formation of stable storage capacitors.

[0041] (15) In a further exemplary embodiment of the first aspect of thepresent invention, the electro-optical device may further include afifth storage capacitor which may include the first capacitor electrode,an insulating film laminated on the first capacitor electrode, and asixth capacitor electrode arranged opposite to the first capacitorelectrode with the insulating film provided therebetween to form thepixel electrode.

[0042] In this exemplary embodiment of the present invention, the fifthstorage capacitor is formed by using the first capacitor electrode,which constitutes the first storage capacitor, and the pixel electrode,and storage capacitors can thus be laminated in the thickness directionof the substrate, thereby permitting the construction of a relativelylarge storage capacitor in the non-aperture region even when the pixelpitch is decreased. Also, the sixth capacitor electrode may include thepixel electrode, and thus storage capacitors can be constructed by alaminated structure consisting of a relatively small number of layers.

[0043] (16) In a further embodiment of the first aspect of the presentinvention, in the electro-optical device, the fifth storage capacitor isformed over the entire periphery of each pixel.

[0044] In this exemplary embodiment of the present invention, a storagecapacitor can be formed by using the peripheral region of each pixel.

[0045] (17) In a second exemplary aspect of the present invention, anelectro-optical device may include a scanning line formed above asubstrate, a data line formed above the substrate, a thin filmtransistor connected to the data line, a pixel electrode connected tothe drain region of the thin film transistor, a channel region of thethin film transistor on which the scanning line is arranged with a gageinsulating film formed therebetween, and a light-shielding conductivefilm which constitutes a capacitor electrode of a storage capacitor andwhich is arranged above the scanning line to cover at least the channelregion of the thin film transistor.

[0046] In this exemplary embodiment of the present invention, the gateinsulating film, the scanning line, and the conductive film arelaminated in this order on the channel region formed on the substrate.In this laminated structure, the channel region can be shielded by thelight-shielding conductive film. Since the conductive film alsofunctions as the capacitor electrode of the storage capacitor, thestorage capacitor can be constructed while sufficiently shielding thechannel region by a laminated structure that may include a relativelysmall number of layers.

[0047] (18) In another exemplary embodiment of the second aspect of thepresent invention, in the electro-optical device, the conductive filmcovers at least portions of the channel region of the thin filmtransistor, the junction region between a source region and the channelregion of the thin film transistor, the junction region between thedrain region and the channel region of the thin film transistor, andsource and drain regions adjacent to the respective junction regions.

[0048] In this construction of the present invention, at least portionsof the channel region, the junction regions between the source-drainregions and the channel region, and the source-drain regions adjacent tothe junction regions are covered with the conductive film, and it isthus possible to shield even the lightly-doped region of the thin filmtransistor having, for example, a LDD structure, from incident light,thereby permitting a further decrease in changes in the properties ofthe thin film transistors.

[0049] (19) In still another embodiment of the second aspect of thepresent invention, in the electro-optical device, the storage capacitormay include a first conductive film which forms one of capacitorelectrodes of the storage capacitor, and a second conductive film whichforms the other capacitor electrode thereof, the second conductive filmelectrically connecting a semiconductor layer constituting the drainregion to the pixel electrode.

[0050] In this exemplary embodiment of the present invention, the secondconductive film which constitutes the other electrode of the storagecapacitor also functions as a conductive film for relaying the drainregion to the pixel electrode, and it is thus possible to preventetching penetration during the formation of a contact hole forconnecting the pixel electrode and the drain region. Namely, the drainregion can be connected to the second conductive film through thecontact hole formed on the drain region, and the pixel electrode can beconnected to the second conductive film through the contact hole formedon the second conductive film to require the two types of contact holes,whereby the etching depth can easily be controlled because of theshortness of the contact holes to prevent the penetration.

[0051] (20) In a further exemplary embodiment of the second aspect ofthe present invention, in the electro-optical device, the secondconductive film covers at least portions of the channel region of thethin film transistor, the junction region between a source region andthe channel region of the thin film transistor, the junction regionbetween the drain region and the channel region of the thin filmtransistor, and the source and drain regions adjacent to the respectivejunction regions.

[0052] In this exemplary embodiment of the present invention, thechannel region is shielded from light by the scanning line arrangedabove the channel region, and the first conductive film, and furthershielded by the second conductive film arranged between the scanningline and the first conductive film, and thus the channel region can beshielded by triple films to further increase the effect of shielding thechannel region.

[0053] (21) In a further exemplary embodiment of the second aspect ofthe present invention, in the electro-optical device, the channel regionis covered with the data line arranged above the first conductive filmwith an insulating film provided therebetween.

[0054] In this exemplary embodiment, since the channel region isshielded by the scanning line formed thereon, and the first conductivefilm, and further shielded by the second conductive film and the dataline arranged thereon, light-shielding can be performed with quadruplefilms, thereby further increasing the effect of shielding the channelregion. Furthermore, since the data line is arranged above the firstconductive film, an increase in temperature due to light absorption bythe first conductive film can be suppressed.

[0055] (22) In a further exemplary embodiment of the second aspect ofthe present invention, the electro-optical device may further include athird conductive film which may consist of the same film as the scanningline, and which is arranged opposite to the second conductive film withan interlayer insulating film provided therebetween.

[0056] In this exemplary embodiment of the present invention, a storagecapacitor can be formed by overlapping the first and second conductivefilms, and a storage capacitor can also be formed by arranging thesecond and third conductive films opposite to each other with theinterlayer insulating film provided therebetween, thereby permittinglamination of storage capacitors in the thickness direction of thesubstrate. Therefore, even when the pixel pitch is decreased, arelatively large storage capacitor can be formed in the non-apertureregion. Since the third conductive film consists of the same film as thescanning line, the storage capacitors can be formed by a laminatedstructure that may include a relatively small number of layers.

[0057] (23) In a further exemplary embodiment of the second aspect ofthe present invention, the electro-optical device may further include afourth conductive film which may consist of the same film as the drainregion, and which is arranged opposite to the third conductive film withthe gate insulating film provided therebetween.

[0058] In this exemplary embodiment of the present invention, since thefourth conductive film may consist of the same film as the drain regionis arranged opposite to the third conductive film with the gateinsulating film provided therebetween, thereby permitting furtherlamination of a storage capacitor in the thickness direction of thesubstrate. Namely, the storage capacitor formed by overlapping the firstand second conductive films, the storage capacitor formed by overlappingthe second and third conductive films, and the storage capacitor formedby overlapping the third and fourth conductive films enable laminationof storage capacitors in the thickness direction of the substrate.Therefore, even when the pixel pitch is decreased, a relatively largestorage capacitor can be formed in the non-aperture region. Since thefourth conductive film may consist of the same film as the drain region,the storage capacitors can be formed by a laminated structure that mayinclude a relatively small number of layers.

[0059] (24) In a further exemplary embodiment of the second aspect ofthe present invention, in the electro-optical device, the firstconductive film and the third conductive film are electrically connectedto each other.

[0060] In this exemplary embodiment of the present invention, twostorage capacitors can be formed with the second conductive film formedtherebetween.

[0061] (25) In a further exemplary embodiment of the second aspect ofthe present invention, in the electro-optical device, the secondconductive film and the fourth conductive film are electricallyconnected to each other.

[0062] In this exemplary embodiment of the present invention, twostorage capacitors can be formed with the third conductive film formedtherebetween.

[0063] (26) In a further exemplary embodiment of the second aspect ofthe present invention, in the electro-optical device, the firstconductive film and the third conductive film are electrically connectedto each other, and the second conductive film and the fourth conductivefilm are electrically connected to each other.

[0064] In this exemplary embodiment of the present invention, a storagecapacitor is formed in a shape in which the first and the thirdconductive films, and the second and fourth conductive films, which arearranged in the thickness direction, are engaged in a comb form.Therefore, a larger storage capacitor can be constructed in thenon-aperture region.

[0065] (27) In a further exemplary embodiment of the second aspect ofthe present invention, in the electro-optical device, the firstconductive film covers the channel region, and the data line is formedon the channel region and the adjacent region thereof so as not toproject from the first conductive film in a plan view.

[0066] In this exemplary embodiment of the present invention, since thefirst conductive film covers the channel region, even with obliqueincident light, incidence on the channel region can be prevented.Furthermore, the data line is formed on the channel region so as not toproject from the first conductive film in a plan view. Since the firstconductive film is formed with a larger width and located nearer to thechannel region, compared with the data line, incidence of oblique lighton the channel region can be prevented, and incidence of reflected lightfrom the data line on the channel region can also be prevented.

[0067] (28) In a further exemplary embodiment of the second aspect ofthe present invention, in the electro-optical device, the firstconductive films may include films having lower reflectance than thedata lines.

[0068] In this exemplary embodiment of the present invention, since thefirst conductive film has lower reflectance than that of the data line,when reflected light reaching the channel region due to oblique returnedlight, or multiple reflected light is reflected by the lower surface ofthe first conductive film, as in the present invention, incident lightcan be attenuated by an amount corresponding to a decrease inreflectance to suppress the influence of reflected light, as comparedwith a case in which light is reflected by the lower surface of the dataline. Namely, in the present invention, even when reflected light ormultiple reflected light from the lower surface of the first conductivefilm reaches the channel region, the light intensity is decreased, andthus a change in the properties of the thin film transistors due to thereflected light can be suppressed. The channel region can also besufficiently shielded from oblique incident light by widening the firstconductive film.

[0069] (29) In a further exemplary embodiment of the second aspect ofthe present invention, in the electro-optical device, each of the firstconductive film and the data line may include a film containing at leastAl.

[0070] In this exemplary embodiment of the present invention, incidentlight can be reflected by the data line and the first conductive film toprevent an increase in the temperature of the electro-optical device anddecrease the resistance of the first conductive film.

[0071] (30) In a further exemplary embodiment of the second aspect ofthe present invention, the electro-optical device may further include anunderlying light-shielding film which is arranged below thesemiconductor layer on the substrate and which is formed to cover atleast the channel region as viewed from the opposite side of thesubstrate, and not to project from the first conductive film in a planview of the channel region and the adjacent region thereof.

[0072] In this exemplary embodiment of the present invention, since thescanning line, the first conductive film and the data line are formedabove the channel region, the channel region can be prevented from beingirradiated with light from above, and the upper and lower side of thechannel region can be shielded because the underlying light-shieldingfilm is further arranged below the channel region. Particularly, theunderlying light-shielding film covers the channel region, and can thusprevent the channel region from being irradiated with light (returnedlight or the like) from the opposite side of the substrate. Furthermore,since the underlying light-shielding film is formed not to project fromthe first conductive film in a plan view of the channel region and theadjacent region thereof, the channel region can be prevented from beingirradiated with incident light reflected by the underlyinglight-shielding film. In addition, even when there is oblique returnedlight which is likely to be incident on the channel region due tomultiple reflection, the returned light is mostly reflected by the firstconductive film having low reflectance and then incident on the channelregion, and thus attenuated light is incident on the channel region,whereby the channel region can be prevented from being irradiated withlight reflected by the data line having high reflectance. Therefore,even when multiple reflection occurs, the influence on the channelregion can be significantly suppressed.

[0073] (31) In a further exemplary embodiment of the second aspect ofthe present invention, in the electro-optical device, at least either ofthe first conductive film and the underlying light-shielding film ismade of a high-melting-point metal.

[0074] In this exemplary embodiment of the present invention, the firstconductive film and the underlying light-shielding film are made of, forexample, a single metal, an alloy, a metal silicide, or the like whichcontains at least one of opaque high-melting-point metals such as Ti(titanium), Cr (chromium), W (tungsten), Ta (tantalum), Mo (molybdenum),Pd (lead), and the like. Therefore, the first conductive film and theunderlying light-shielding film can be prevented from being broken ormelted by high-temperature treatment. For example, in the use of Al(aluminum) generally used as a material for the data line, the data linehas a reflectance of over 80%, while the first conductive film made of ahigh-melting-point metal such as Ti, Cr, W, or the like, has reflectancesignificantly lower than the reflectance of the data line, whereby theeffect of the present invention can be sufficiently exhibited.

[0075] (32) In a further exemplary embodiment of the second aspect ofthe present invention, in the electro-optical device, the firstconductive film has substantially the same size as the second conductivefilm under the data line.

[0076] In this exemplary embodiment, since the first conductive film hassubstantially the same size as the second conductive film, light can beprevented from entering the channel layer due to internal reflection bythe first conductive film, and the area of the first conductive film canbe increased to enlarge storage capacitors.

[0077] (33) In a further exemplary embodiment of the second aspect ofthe present invention, in the electro-optical device, the firstconductive film is extended from the image display region in which thepixel electrode is arranged to the periphery thereof, and connected to aconstant potential source in the peripheral region.

[0078] In this exemplary embodiment, the first conductive film functionsnot only as the light-shielding film but also as an electrode of thestorage capacitor, which functions as a capacitor line, and thus astorage capacitor which may include the capacitor electrode in which thecapacitor line is connected to the constant potential source, can beformed in a laminated structure which may include a relatively smallnumber of layers while sufficiently shielding the channel region. Inthis case, the capacitor electrode may include the first conductivefilm, or the capacitor electrode and the other capacitor line (lengthycapacitor line) may include a conductive film different from the firstconductive film. In addition, the capacitor electrode can be connectedto the constant potential source by effectively using thelight-shielding region (the non-aperture region of each pixel). As theconstant potential source, a constant potential source for peripheralcircuits such as a data line driving circuit, a scanning line drivingcircuit, can be used, and an exclusive constant potential source neednot be provided to exhibit good efficiency.

[0079] (34) In a further exemplary embodiment of the second aspect ofthe present invention, in the electro-optical device, the thirdconductive film may include the capacitor line which is extended fromthe image display region to the periphery thereof along the scanningline, and connected to the constant potential source in the peripheralregion, the first conductive film being connected to the capacitor line.

[0080] In this exemplary embodiment, the first conductive film isconnected to the capacitor line, and thus the potential of the firstconductive film can be kept constant through the capacitor line toprevent the situation in which the properties of the thin filmtransistor are adversely affected by a change in the potential of thefirst conductive film, even when the first conductive film is arrangednear the channel region. When the first conductive film is used as thecapacitor line, the potential of the first conductive film can be fixedby the capacitor line, and thus the first conductive film satisfactorilyfunctions as the capacitor electrode.

[0081] (35) In a further exemplary embodiment of the second aspect ofthe present invention, in the electro-optical device, the underlyinglight-shielding film may include a light-shielding conductive film, andis connected to the capacitor line for each pixel.

[0082] In this exemplary embodiment, the underlying light-shielding filmis connected to the capacitor line for each pixel, and thus thepotential of the underlying light-shielding film can be kept constantthrough the capacitor line to prevent the situation in which theproperties of the thin film transistors are adversely affected by achange in the potential of the underlying light-shielding films, evenwhen the underlying light-shielding film is arranged near the channelregion. When the underlying light-shielding film is used as thecapacitor electrode, the potential of the underlying light-shieldingfilm can be fixed by the capacitor line, and thus the underlyinglight-shielding film satisfactorily functions as the capacitorelectrode.

[0083] (36) In a third exemplary aspect of the present invention, anelectro-optical device may include a thin film transistor, a data lineelectrically connected to a semiconductor layer of the thin filmtransistor through a first connection portion, a scanning lineoverlapped with the semiconductor layer of the thin film transistor, apixel electrode electrically connected to the semiconductor layer of thethin film transistor through a second connection portion, and alight-shielding film arranged in a region including the data line andthe scanning line except the first and second connection portions.

[0084] In this exemplary embodiment construction of the presentinvention, a region with a poor contrast ratio produced in the peripheryof the pixel electrode can be shielded by the light-shielding film.

[0085] (37) In another exemplary embodiment of the third aspect of thepresent invention, in the electro-optical device, the light-shieldingfilm overlaps with the edge of the pixel electrode.

[0086] In this exemplary embodiment of the present invention, theregions including the data line and the scanning line can be shielded bythe light-shielding film to define the non-aperture region.

[0087] (38) In still another exemplary embodiment of the third aspect ofthe present invention, the electro-optical device may further include anunderlying light-shielding film provided below the semiconductor layerso that at least a portion of the thin film transistor is held betweenthe light-shielding film and the underlying light-shielding film.

[0088] In this exemplary embodiment of the present invention, lightincidence on the thin film transistor can be prevented by thelight-shielding film and the underlying light-shielding film to suppressa change in the properties of the thin film transistor.

[0089] (39) In a further exemplary embodiment of the third aspect of thepresent invention, in the electro-optical device, the underlyinglight-shielding film is extended along either of the data line and thescanning line.

[0090] In this exemplary embodiment of the present invention, thelight-shielding performance of the non-pixel aperture regions can beincreased only by the substrate having the thin film transistor.

[0091] (40) In a still further exemplary embodiment of the third aspectof the present invention, in the electro-optical device, ananti-reflection film is formed on at least the side of the underlyinglight-shielding film opposite to the thin film transistor side thereof.

[0092] In this exemplary embodiment of the present invention, when lightis incident on the underlying light-shielding film, the anti-reflectionfilm can prevent reflection of the light to the channel region and theregion adjacent to the channel region of the thin film transistor.

[0093] (41) In a further exemplary embodiment of the third aspect of thepresent invention, the electro-optical device may further include aconductive relay film for electrically connecting the semiconductorlayer and the pixel electrode.

[0094] In this exemplary embodiment of the present invention, etchingpenetration due to the formation of contact holes for connecting thepixel region and the drain region can be prevented.

[0095] (42) In a further exemplary embodiment of the third aspect of thepresent invention, in the electro-optical device, the relay film isarranged in a region including the data line and the scanning lineexcept the first connection portion for connecting the semiconductorlayer and the data line.

[0096] In this exemplary embodiment of the present invention, thelight-shielding performance can be improved while securing the firstconnection portion for connecting the semiconductor layer and the dataline.

[0097] (43) In a further exemplary embodiment of the third aspect of thepresent invention, in the electro-optical device, the relay film isarranged in the second connection portion between the semiconductorlayer and the pixel electrode, which is avoided from the light-shieldingfilm.

[0098] In this exemplary embodiment of the present invention, the secondconnection portion between the semiconductor layer and the pixelelectrode, which cannot be shielded by the light-shielding film, can beshielded to completely shield the region along the scanning line.

[0099] (44) In a further exemplary embodiment of the third aspect of thepresent invention, in the electro-optical device, the data line is madeof a light-shielding material.

[0100] In this exemplary embodiment of the present invention, thelight-shielding performance can be further improved.

[0101] (45) In a further exemplary embodiment of the third aspect of thepresent invention, in the electro-optical device, a space is formedbetween the data line and the pixel electrode, and the light-shieldingfilm is arranged in the space.

[0102] In this exemplary embodiment of the present invention, aparasitic capacitor between the data line and the pixel electrode can bedecreased, and the space therebetween can be shielded by thelight-shielding film to define the pixel aperture region.

[0103] (46) In a further exemplary embodiment of the third aspect of thepresent invention, in the electro-optical device, the data line isarranged in the first connection portion between the semiconductor layerand the data line, which is avoided from the light-shielding film.

[0104] In this exemplary embodiment of the present invention, the firstconnection portion between the semiconductor layer and the data line,which cannot be shielded by the light-shielding film, can be shielded tocompletely shield the region along the data line.

[0105] (47) In a further exemplary embodiment of the third aspect of thepresent invention, in the electro-optical device, the non-pixel apertureregion may include the light-shielding film and the underlyinglight-shielding film.

[0106] In this exemplary embodiment of the present invention, thelight-shielding performance of the thin film transistor can be improvedby shortening the distance between the light-shielding film and theunderlying light-shielding film.

[0107] (48) In a further exemplary embodiment of the third aspect of thepresent invention, in the electro-optical device, the scanning line isextended to substantially the center of the non-pixel aperture region.

[0108] In this exemplary embodiment of the present invention, if thecapacitor electrode which constitutes the storage capacitor need not bemade of the same film as the scanning line, the scanning line can beextended to substantially the center of the non-pixel aperture region toimprove the light-shielding performance of the channel region of thethin film transistor and the adjacent region thereof.

[0109] (49) In a further exemplary embodiment of the third aspect of thepresent invention, in the electro-optical device, in the periphery ofthe thin film transistor including the channel region, the relay film islocated in a region inward of the light-shielding film, and theunderlying light-shielding film is located in a region inward of therelay film.

[0110] In this exemplary embodiment of the present invention, lightincident from the light-shielding film side is not incident directly onthe underlying light-shielding film so that incidence of light reflectedby the underlying light-shielding film on the thin film transistor canbe decreased.

[0111] (50) In a further exemplary embodiment of the third aspect of thepresent invention, in the electro-optical device, the semiconductorlayer is located in a region inward of the data line.

[0112] In this exemplary embodiment of the present invention, thesemiconductor layer is formed in a region inward of the data line, andthus incidence of light on the semiconductor layer can be decreased.Therefore, the semiconductor layer is not extended along the scanningline, whereby the pitch of the non-pixel aperture regions can bedecreased, and the light-shielding performance can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS

[0113]FIG. 1 is a drawing of equivalent circuits including variouselements, wiring, etc. provided on a plurality of pixels which arearranged in a matrix and which constitute an image display region of anelectro-optical device in accordance with a first exemplary embodimentof the present invention;

[0114]FIG. 2 is a plan view of a plurality of adjacent pixel groups of aTFT array substrate on which data lines, scanning lines, pixelelectrodes, etc. are formed in the electro-optical device in accordancewith the first embodiment;

[0115]FIG. 3 is a sectional view taken along line III-III′ in FIG. 2;

[0116]FIG. 4 is a drawing of an equivalent circuit of each of pixelswhich constitute an electro-optical device in accordance with anexemplary embodiment of the present invention;

[0117]FIG. 5 is a plan view showing the light-shielding conductivefilms, and the relay films shown in FIG. 2;

[0118]FIG. 6 is a plan view showing the relay films and the capacitorelectrodes shown in FIG. 2;

[0119]FIG. 7 is a plan view showing the capacitor electrodes and thesemiconductor layers shown in FIG. 2;

[0120]FIG. 8 is a plan view showing the semiconductor layers and theunderlying light-shielding films shown in FIG. 2;

[0121]FIG. 9 is a plan view showing the light-shielding conductive filmsand the pixel electrodes shown in FIG. 2;

[0122]FIG. 10 is a plan view showing the underlying light-shieldingfilms, the light-shielding conductive films, the relay films and thedata lines shown in FIG. 2;

[0123]FIG. 11(A) is a sectional view taken along line XI-XI′ in FIG. 2,and FIG. 11(B) is a sectional view of a related structure;

[0124]FIG. 12 is a schematic drawing showing the polarities of imagesignals supplied to a plurality of pixel electrodes which are arrangedin a matrix and which constitute an image display region of anelectro-optical device in accordance with a second exemplary embodimentof the present invention;

[0125]FIG. 13 is a plan view of a plurality of adjacent pixel groups ofa TFT array substrate on which data lines, scanning lines, pixelelectrodes, etc. are formed in the electro-optical device in accordancewith the second embodiment;

[0126]FIG. 14 is a sectional view taken along line XIV-XIV′ in FIG. 13;

[0127]FIG. 15 is a sectional view taken along line XV-XV′ in FIG. 13;

[0128]FIG. 16 is a sectional view taken along line XVI-XVI′ in FIG. 13;

[0129]FIG. 17 is a plan view of a plurality of adjacent pixel groups ofa TFT array substrate on which data lines, scanning lines, pixelelectrodes, etc. are formed in the electro-optical device in accordancewith a third exemplary embodiment;

[0130]FIG. 18 is a sectional view taken along line XVIII-XVIII′ in FIG.17;

[0131]FIG. 19 is a plan view of a plurality of adjacent pixel groups ofa TFT array substrate on which data lines, scanning lines, pixelelectrodes, etc. are formed in the electro-optical device in accordancewith a fourth exemplary embodiment;

[0132]FIG. 20 is a sectional view taken along line XX-XX′ in FIG. 19;

[0133]FIG. 21 is a plan view the TFT array substrate and the componentsformed thereon in a liquid crystal device in accordance with anexemplary embodiment, as viewed from the counter substrate side;

[0134]FIG. 22 is a sectional view taken along line XXII-XXII′ in FIG.21.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0135] Exemplary embodiments of the present invention will be describedbelow with reference to the drawings.

[0136] (First Exemplary Embodiment)

[0137] The construction of a liquid crystal device as an example of anelectro-optical device of the present invention will be described withreference to FIGS. 1 to 11(B). FIG. 1 is a drawing showing equivalentcircuits which include various elements, wiring, etc. of a plurality ofpixels which constitute an image display region of the liquid crystaldevice and which are formed in a matrix, FIG. 2 is a plan view of aplurality of adjacent pixel groups of a TFT array substrate on whichdata lines, scanning lines, pixel electrodes, etc. are formed, and FIG.3 is a sectional view taken along line III-III′ in FIG. 2. In FIG. 3,layers and members are shown on different reduction scales in order tomake each of the layers and the members recognizable in the drawing.

[0138] In FIG. 1, in a plurality of pixels which constitute the imagedisplay region of the liquid crystal device of this embodiment and whichare formed in a matrix, pixel electrodes 9 a and TFTs 30 for controllingthe pixel electrodes 9 a are formed, and data lines 6 a to which imagesignals are supplied are electrically connected to the sources of theTFTs 30. Image signals S1, S2, . . . , Sn to be written on the datalines 6 a may be supplied in this order in line sequence, or supplied toeach group of the adjacent data lines 6 a. Furthermore, scanning lines 3a are electrically connected to the gates of the TFTs 30 so thatscanning signals G1, G2, . . . Gm are applied to the scanning lines 3 ain this order in line sequence with predetermined timing. The pixelelectrodes 9 a are electrically connected to the drains of the TFTs 30so that the TFTs 30 respectively serving as switching elements areswitched off for a predetermined time to write the image signals S1, S2,. . . , Sn supplied from the data lines 6 a with predetermined timing.The image signals S1, S2, . . . , Sn at the predetermined level writteninto a liquid crystal through the pixel electrodes 9 a are maintainedbetween the pixel electrodes 9 a and a counter electrode (describedbelow) formed on a counter substrate (described below) for thepredetermined time. The liquid crystal modulates light due to a changein the molecular orientation and order according to the level of theapplied voltage to enable gray scale display. In a normally white mode,the quantity of transmitted light of incident light increases accordingto the applied voltage, while in a normally black mode, the quantity oftransmitted light of incident light increases according to the appliedvoltage to emit light from the liquid crystal device as a whole with acontrast ratio corresponding to the image signals. In order to prevent aleakage of the maintained image signals, storage capacitors 70 are addedin parallel to the liquid crystal capacitor formed between the pixelelectrodes 9 a and the counter electrode. Each of the storage capacitors70 is formed between one of capacitor electrodes electrically connectedto each of the pixel electrodes 9 a and the other capacitor electrodeelectrically connected to a corresponding capacitor line 300 to which aconstant potential is supplied, through a dielectric film. For example,each of the storage capacitors 70 functions to maintain the voltage ofthe corresponding pixel electrode 9 a for a time three orders ofmagnitude longer than the time of application of a source voltage. Thiscan further improve the holding property to realize a bright crystaldevice with a high contrast ratio.

[0139] In FIG. 2, a plurality of the transparent pixel electrodes 9 a(the pixel electrode ends 9 a′ shown by dotted lines) are provided in amatrix on the TFT array substrate of the liquid crystal device, and thedata lines 6 a and the scanning lines 3 a are provided along thelongitudinal and lateral boundaries between the pixel electrodes 9 a.The scanning lines 3 a are arranged opposite to the channel regions 1 a′(the regions shown by slanted lines in the drawing) of semiconductorlayers 1 a, and function as gate electrodes. In this embodiment, TFT 30is provided at each of the intersections of the scanning lines 3 a andthe data lines 6 a, in which each of the scanning lines 3 a is partiallyopposed as the gate electrode to the corresponding channel region 1 a′.Each of the pixel electrodes 9 a is electrically connected to the drainof the corresponding semiconductor layer 1 a, which will be describedbelow, by relaying a relay film 80 a serving as an intermediateconductive film through contact holes 8 a and 8 b. The data lines 6 aare electrically connected to the source regions of the semiconductorlayers 1 a consisting of a polysilicon film or the like, which will bedescribed below, through contact holes 5.

[0140] Also, capacitor electrodes 3 b (third capacitor electrodes)consisting of the same film as the scanning lines 3 a may be provided soas to overlap with at least portions of capacitor electrodes 1 f (fourthcapacitor electrodes), which are extended from the semiconductor layers1 a, through gate insulating films described below. This permits theformation of at least portions of the storage capacitors 70 shown inFIG. 1.

[0141] In each of the regions shown by bold lines in FIG. 2, anunderlying light-shielding film 11 a is provided along the correspondingscanning line 3 a so as to pass through the portion below the TFTs 30.More specifically, the underlying light-shielding films 11 a areprovided to cover at least the TFT channel regions 1 a′ and the junctionregions between the channel regions 1 a′ and the source and drainregions, as viewed from the TFT array substrate side. Also, theunderlying light-shielding films 11 a are preferably extended along thedirection of the scanning lines 3 a to the periphery of the imagedisplay region in which the pixel electrodes 9 a are formed in a matrixto be connected to a constant potential source in the periphery region.In this way, by fixing the potential of the underlying light-shieldingfilms 11 a to the constant potential, operational errors of the TFTs 30can be prevented. As the constant potential source, a constant potentialsource such as a negative power source, a positive power source suppliedto peripheral circuits for driving the liquid crystal device, forexample, a scanning line driving circuit, a data line driving circuit,which will be described below, a ground power source, a constantpotential source supplied to the counter electrode, or the like can beused. The potential level is preferably the off level of scanningsignals supplied to the scanning lines 3 a. As a result, substantiallyno parasitic capacitance occurs between the underlying light-shieldingfilms 11 a and the scanning lines 3 a, thereby causing substantially nodelay in the scanning signals supplied to the scanning lines 3 a.

[0142] Particularly, in this embodiment, a light-shielding conductivefilm (first capacitor electrode) 90 a is formed in each of the regionsshown by slanted lines in FIG. 2. The light-shielding conductive films90 a are formed between the scanning lines 3 a and the data lines 6 a sothat in a plan view, the light-shielding conductive films 90 a can beoverlapped with the regions where wiring such as the data lines 6 a andthe scanning lines 3 a, the TFTs 30 and the storage capacitors areformed, except the regions of the contact holes 5 and the contact holes8 b, thereby permitting the realization of light shielding on the TFTarray substrate. Also, the light-shielding conductive films 90 a can beextended to the periphery of the image display region along the scanninglines 3 a to be connected to a constant potential source in theperipheral region. As a result, the light-shielding conductive films 90a can function as the capacitor lines 300 shown in FIG. 1. Also, thelight-shielding conductive films 90 a can be connected to the capacitorelectrodes 3 b consisting of the same film as the scanning lines 3 athrough contact holes 95 so that the storage capacitors 70 can easily beformed between the capacitor electrodes 3 b and the capacitor electrodes1 f by supplying a constant potential. As a constant potential source,the constant potential source such as the negative power source, thepositive power source supplied to the peripheral circuits for drivingthe liquid crystal device, for example, the scanning line drivingcircuit, the data line driving circuit, which will be described below,the ground power source, the constant potential source supplied to thecounter electrode, or the like can be used.

[0143] As shown in a sectional view of FIG. 3, the liquid crystal deviceof this embodiment may include a transparent TFT array substrate 10which constitutes an example of substrates, and a transparent countersubstrate 20 arranged to opposite to the TFT array substrate 10. Forexample, the TFT array substrate 10 may include a quartz substrate, aglass substrate, or a silicon substrate, and the counter substrate 20may include a glass substrate or a quartz substrate. The TFT arraysubstrate 10 may include the pixel electrodes 9 a provided thereon andincluding a transparent conductive film such as an ITO film. In the useof a TN (Twisted Nematic) liquid crystal or the like for a liquidcrystal layer 50, an alignment film 16 subjected to predeterminedorientation by rubbing or the like is provided on the surfaces of thepixel electrodes 9 a.

[0144] On the other hand, a counter electrode 21 consisting of atransparent conductive film such as a ITO film is provided over theentire surface of the counter substrate 20, and an alignment film 22subjected to predetermined orientation by rubbing or the like isprovided on the surface of the counter electrode 21.

[0145] Furthermore, the underlying light-shielding films 11 a arerespectively provided at positions opposite to the TFTs 30 between theTFT array substrate 10 and the TFTs 30. The underlying light-shieldingfilms 11 a are formed opposite to at least the channel regions 1 a′ ofthe switching TFTs 30, and the junction regions between the channelregions 1 a′ and the source and drain regions, whereby preventingirradiation of the channel regions 1 a′ and the adjacent regions thereofwith reflected light from the TFT array substrate 10 side. Therefore,the properties of the TFTs 30 are not changed by the occurrence of aleakage current due to light. The underlying light-shielding conductivefilms 11 a are preferably made of a single metal, an alloy, a metalsilicide, or the like, which contains at least one of opaquehigh-melting-point metals such as Ti (titanium), Cr (chromium), W(tungsten), Ta (tantalum), Mo (molybdenum), Pb (lead). Alternatively,anti-reflection films of polysilicon or the like may be formed on thesurfaces of the underlying light-shielding films 11 a in order to absorblight even when incident light directly enters the TFTs 30. With weakreflected light from the TFT array substrate 10 side, a polysilicon filmmay be used for the underlying light-shielding films 11 a. By formingthe underlying light-shielding films 11 a using such a material, forexample, the underlying light-shielding films 11 a can be prevented frombeing broken or melted by high-temperature treatment for forming gateinsulating films 2. Although, in this embodiment, the underlyinglight-shielding films 11 a are formed in strips along the scanning lines3 a below the scanning lines 3 a, of course, the underlyinglight-shielding films 11 a may be formed in strips along the data lines6 a below the data lines 6 a, or formed in a lattice form below thescanning lines 3 a and the data lines 6 a. By forming the underlyinglight-shielding films 11 a in strips, relief of stress due to theunderlying light-shielding films 11 a can be realized, while by formingthen in a lattice form, the high-shielding performance can be improvedand the resistance of the underlying light-shielding films 11 a can befurther decreased.

[0146] Furthermore, an underlying insulating film 12 is provided betweenthe underlying light-shielding films 11 a and the TFTs 30. Theunderlying insulating film 12 is provided for electrically insulatingthe semiconductor layers 1 a which constitute the TFTs 30 from theunderlying light-shielding films 11 a. Furthermore, the underlyinginsulating film 12 is formed over the entire surface of the TFT arraysubstrate 10 to have the function as an underlying film for the TFTs 30.Namely, the underlying insulating film 12 has the function of preventingroughening of the surface of the TFT array substrate 10 duringpolishing, and a change in the properties of the TFTs 30 due to stainsremaining after cleaning. The underlying insulating film 12 may consistof, for example, a highly insulating glass film of NSG (nondopedsilicate glass), PSG (phosphosilicate glass), BSG (boron silicateglass), BPSG (boron phosphosilicate glass), or the like, a silicon oxidefilm, a silicon nitride film. The underlying insulating film 12 can alsoprevent the situation that the TFTs 30 are contaminated by theunderlying light-shielding films 11 a.

[0147] In this embodiment, furthermore, each of the TFTs 30 formed onthe underlying insulating film 12 has an LDD (Lightly Doped Drain)structure in which the semiconductor which layer 1 a may consist of, forexample, a polysilicon film, may consist of a lightly-doped sourceregion 1 b and a lightly-doped drain region 1 c with the channel region1 a′ in which a channel is formed by an electric field supplied from thecorresponding scanning line 3 a, heavily-doped source and drain regions1 d and 1 e being connected to the lightly-doped source and drainregions 1 b and 1 c, respectively. In this way, by forming the LDDstructure TFTs 30, a leakage current of the TFTs 30 in an off state canbe significantly decreased to improve the holding performance. Each ofthe TFTs 30 may have an offset structure in which the lightly-dopedsource region 1 b and the lightly-doped drain region 1 c are not dopedwith impurities, or a self alignment TFT structure in which aheavily-doped of impurity is implanted by using the gate electrode whichmay include a part of the corresponding scanning line 3 a as a mask toform the heavily-doped source region Id and the heavily-doped drainregion 1 e in a self alignment manner.

[0148] The gate insulation thin films 2 of 100 nm or less are formed onthe semiconductor layers 1 a. The gate insulating films 2 can be formedby oxidizing a polysilicon film at a high temperature of 1000° C. ormore to form a film having high density and insulation. Whenhigh-temperature treatment cannot be carried out, the gate insulatingfilms 2 may be formed by CVD (Chemical Vapor Deposition), or the like.The scanning lines 3 a consisting of a low-resistance polysilicon filmin which, for example, P (phosphorus) is implanted, are arranged on thegate insulating films 2 so that the portions of the scanning lines 3 aoverlapped with the semiconductor layers 1 a function as the gateelectrodes.

[0149] Furthermore, an interlayer insulating film 81 is deposited on thegate insulating films 2 and the scanning lines 3 a formed on thesemiconductor layers 1 a by CVD or the like, and the contact holes 8 aare formed in the gate insulating films 2 and the interlayer insulatingfilm 81 at the predetermined positions of the heavily-doped drainregions 1 e. The heavily-doped drain regions 1 e are electricallyconnected to the conductive relay films 80 a through the contact holes 8a. Furthermore, interlayer insulating films 91, 4 and 7 are laminated inturn on the relay films 80 a, and the contact holes 8 b are formed inthese interlayer insulating films at positions of the relay films 80 a(second capacitor electrodes). The relay films 80 a are electricallyconnected to the pixel electrodes 9 a through the contact holes 8 b.Therefore, the relay films 80 a function as intermediate conductivefilms for electrically connecting the semiconductor layers 1 a and thepixel electrodes 9 a. By forming the relay films 80 a, long contactholes need not be formed from the pixel electrodes 9 a to thesemiconductor layers 1 a, and thus penetration in the thin semiconductorlayers 1 a having a thickness of, for example, about 50 nm, can beprevented. The formation of the separate contact holes has the advantagethat the diameter of either of the contact holes 8 a and 8 b can bedecreased. Therefore, the regions of the contact holes 8 a and 8 b canbe decreased to increase the pixel aperture ratio and realize highdefinition. Like the underlying light-shielding films 11 a, the relayfilms 80 a are formed by using a material such as a single metal, analloy, a metal silicide, which contains at least one of opaquehigh-melting-point metals such as Ti, Cr, W, Ta, Mo, Pb, therebypermitting the relay films 80 a to function as light-shielding films.Furthermore, even when the relay films 80 a are formed to a thickness ofabout 50 nm, no penetration in the relay films 80 a occurs during theformation of the contact holes 8 b because of a high etching selectionratio. When the interlayer insulating film 81 for insulating thescanning lines 3 a from the relay films 80 a is formed to a thicknessof, for example, 500 nm or more, which has no influence on the switchingoperation of the TFTs 30, the relay films 80 a can be provided tooverlap with the TFTs 30 and the scanning lines 3 a in a plan view.Therefore, light shielding can be realized below the data lines 6 a nearthe semiconductor layers 1 a which constitute the TFTs 30, therebypreventing the channel regions 1 a′ and the lightly-doped source regions1 b and the lightly-doped drain regions 1 c, which serve as the junctionregions, from being irradiated directly with incident light and straylight reflected by the data lines 6 a and the like. As a result, aleakage current of the TFTs 30 in an off state can be significantlydecreased to further increase the holding performance.

[0150] In this embodiment, as shown in FIG. 3, light-shieldingconductive films 90 a are formed on the relay films 80 a with theinterlayer insulating film 91 provided therebetween. As described above,the light-shielding conductive films 90 a can shield the non-apertureregions except the contact holes 5 and 8 b. Since the light-shieldingconductive films 90 a can also function as the capacitor lines 300 shownin FIG. 1, at least portions of the storage capacitors 70 can be formedby using the interlayer insulating film 91 as a dielectric film betweenthe conductive films 90 a and the relay films 80 a. Namely, the relayfilms 80 a and the light-shielding conductive films 90 a function aselectrodes for forming the storage capacitors 70. Light shielding canalso be realized near the semiconductor layers 1 a, which constitute theTFTs 30, by two layers including the relay films 80 a and thelight-shielding conductive films 90 a. Therefore, a leakage current ofthe TFTs 30 in an off state can be further decreased to cause anadvantage for a liquid crystal device such as a projection projectorused under a strong light source. Like the underlying light-shieldingfilms 11 a or the relay films 80 a, the light-shielding conductive films90 a are formed by using a material such as such as a single metal, analloy, a metal silicide, which contains at least one of opaquehigh-melting-point metals such as Ti, Cr, W, Ta, Mo, Pb, therebypermitting the realization of wiring having high light shieldingperformance and low resistance. When performing high-temperaturetreatment at 400° C. or more, for example, activation heat treatment isterminated before the light-shielding conductive films 90 a are formed,the light-shielding conductive films 90 a can be formed by using asingle metal, an alloy, a metal silicide, or the like containinglow-resistance Al (aluminum). By forming the light-shielding conductivefilms 90 a serving as the capacitor lines 300 using Al which is the samematerial as the data lines 6 a, the resistance of the capacitor lines300 can be made smaller than a conventional polysilicon film by two orthree orders of magnitude. As a result, the crosstalk in the directionof the scanning lines 3 a, which is due to the high time constant of thecapacitor lines 300, can be significantly decreased.

[0151] The light-shielding conductive films 90 a may be electricallyconnected to the capacitor electrodes 3 b consisting of the same film asthe scanning lines 3 a through the contact holes 95 for the respectivepixel electrodes 9 a. As a result, the capacitor electrodes 3 b can befixed at the same constant potential as the light-shielding conductivefilms 90 a. Therefore, at least portions of the storage capacitors 70can be formed between the capacitor electrodes 3 b and the relay films80 a electrically connected to the heavily-doped drain regions 1 e ofthe semiconductor layers 1 a by using the interlayer insulating film 81as a dielectric film. Furthermore, at least portions of the storagecapacitors 70 can also be formed between the capacitor electrodes 3 band the capacitor electrodes If extended from the heavily-doped drainregions 1 e of the semiconductor layers 1 a by using the gate insulatingfilms 2 as dielectric films. The contact holes 95 are formed below thedata lines 6 a so that the semiconductor layers 1 a connected to thepixel electrodes 9 a adjacent along the data lines 6 a are preferablyelectrically connected to the data lines 6 a near the contact holes 5.By using this construction, large regions for forming the storagecapacitors 70 can be secured below the data lines 6 a.

[0152]FIG. 4 is a drawing showing an equivalent circuit of each of thepixels which constitute the liquid crystal device of this embodiment. Asshown in FIG. 4, the heavily-doped drain region 1 e of the semiconductorlayer 1 a is electrically connected to the relay film 80 a and the pixelelectrode 9 a, while the light-shielding conductive film 90 a iselectrically connected to the capacitor electrode 3 b. Thelight-shielding conductive film 90 a is extended from the image displayregion to the periphery thereof to be connected to the constantpotential source in the peripheral region. The underlyinglight-shielding film 11 a may be electrically connected to thelight-shielding conductive film 90 a. These conductive films arecombined to form the storage capacitors 70 having an ideal stackedstructure. Namely, in this embodiment, the capacitor electrode 1 f, therelay film 80 a and the pixel electrode 9 a can be formed between therespective conductive film layers of the light-shielding conductive film90 a fixed at the constant potential, the capacitor electrode 3 b andthe underlying light-shielding film 11 a through dielectric films.

[0153] Specifically, in a plane view of the adjacent pixel groups inFIG. 2, the regions where the storage capacitors are formed are shown inFIGS. 5 to 9. In FIGS. 2 and 5 to 9, the reduction scales are the same.

[0154]FIG. 5 shows first storage capacitors C1 formed at positionsbetween the layer of the scanning lines 3 a and the layer of the datalines 6 a, and between the light-shielding conductive films 90 a and therelay films 80 a. The interlayer insulating film 91 is used as adielectric film. The crosshatched regions are actual regions where thefirst storage capacitors C1 are actually formed, and the first storagecapacitors C1 can be for formed in the significant portions of thenon-aperture regions except the contact holes 5, 95 and 8 b. When thecapacitor electrodes 3 b are not provided, the contact holes 95 forelectrically connecting the capacitor electrodes 3 b to thelight-shielding conductive films 90 a need not be formed, therebypermitting the formation of the first storage capacitors C1 in theregions of the contact holes 95. In this embodiment, the first storagecapacitors C1 can be formed above the channel regions 1 a′ of the TFTs30, which is impossible in a conventional device, thereby causing anadvantage for improving the pixel aperture ratio and definition of atransmissive liquid crystal device. The interlayer insulating film 91can be formed by using a film having high insulation and high dielectricconstant, such as an oxide film, a nitride film. Where the relay films80 a consist of a polysilicon film, and the light-shielding conductivefilms 90 a consist of a multilayer structure including a polysiliconfilm as a lower layer, and a light-shielding film containing ahigh-melting-point metal as an upper layer, the interlayer insulatingfilm 91 can be formed by a continuous step using a polysilicon film,thereby permitting the formation of an insulating film having highdensity and less defect. Therefore, the defects of the device aredecreased, and the interlayer insulating film 91 a having a thickness of100 nm or less can be formed to further enlarge the first storagecapacitors C1.

[0155]FIG. 6 shows second storage capacitors C2 formed between the relayfilms 80 a and the capacitor electrodes 3 b. The interlayer insulatingfilm 81 is used as a dielectric film. The crosshatched regions areregions where the second storage capacitors C2 are actually formed. Thecapacitor electrodes 3 b are parted in the regions of the contact holes8 a for electrically connecting the semiconductor layers 1 a and therelay films 80 a in the respective pixels, and are electricallyconnected to the upper light-shielding conductive films 90 a through thecontact holes 95. As shown in FIG. 6, the capacitor electrodes 3 b areformed in a T shape so that the second storage capacitors C2 can beefficiently formed. As the interlayer insulating film 81, a film havinghigh insulation and a high dielectric constant, such as an oxide film, anitride film can be formed. However, since the capacitor electrodes 3 bconsist of the same film as the scanning lines 3 a, the regions wherethe second storage capacitors C2 can be formed become smaller than theregions where the first storage capacitors C1 are formed, as shown inFIG. 5. In addition, when the channel regions 1 a′ and the adjacentregions thereof are shielded from light by the relay films 80 a, thethickness of the interlayer insulating film 81 must be 500 nm or more inorder to prevent an operation error of the TFTs 30, and thus the secondstorage capacitors C2 cannot be so much enlarged as the first storagecapacitors C1 can be enlarged.

[0156]FIG. 7 shows third storage capacitors C3 formed between thecapacitor electrodes 3 b and the capacitor electrodes 1 f. The gateinsulating films 2 are used as dielectric films. The crosshatchedregions are regions where the third storage capacitors C3 are actuallyformed. Since the gate insulating films 2 are formed by oxidation at ahigh temperature of 1000° C. or more, as described above, a film havinghigh density and insulation can be obtained. Therefore, the regionswhere the third storage capacitors C3 can be formed are substantiallythe same as the regions where the second storage capacitors C2 shown inFIG. 6 are formed, but the regions of the third storage capacitors C3can be made larger than the regions of the second storage capacitors C2.The third storage capacitors C3 can also be formed below the regions ofthe contact holes 95 for electrically connecting the capacitorelectrodes 3 b and the upper light-shielding conductive films 90 a.

[0157] Furthermore, as shown in FIG. 8, fourth storage capacitors C4 canbe formed between the capacitor electrodes 1 f and the underlyinglight-shielding films 11 a. The underlying insulating film 12 is used asa dielectric film. The crosshatched regions are regions where the fourthstorage capacitors C4 are actually formed. When the underlyinginsulating film 12 is formed to a thickness of 500 nm or less, thedistance between the channel regions 1 a′ and the underlyinglight-shielding films 11 a is decreased to cause an operation error ofthe TFTs 30 according to the potential of the underlying light-shieldingfilms 11 a. Therefore, the underlying insulating film 12 may beselectively partially thinned in the regions where the capacitorelectrodes 1 f overlap with the underlying light-shielding films 11 a ina plan view to enlarge the fourth storage capacitors C4. Namely, theportions of the underlying insulating film 12 other than the portionsopposite to the channel regions 1 a′ can be thinned to enlarge thefourth storage capacitors C4.

[0158] Furthermore, as shown in FIG. 9, fifth storage capacitors C5 canbe formed between the pixel electrodes 9 a and the light-shieldingconductive films 90 a. The interlayer insulating films 4 and 7 are usedas dielectric films. The crosshatched regions are regions where thefifth storage capacitors C5 are actually formed. Each of the interlayerinsulating films 4 and 7 consists of a highly insulating glass film of,for example, NSG, PSG, BSC, BPSQ a silicon oxide film, a silicon nitridefilm, or the like. However, since the data lines 6 a are formed on theinterlayer insulating film 4, the interlayer insulating film 7 must bethickly formed because a display image deteriorates due to the parasiticcapacitor produced between the pixel electrodes 9 a and the data lines 6a, and thus the fifth storage capacitors C5 cannot be so much enlargedas the first storage capacitors C1 can be enlarged.

[0159] In this way, in the liquid crystal device of this embodiment, bylaminating the capacitor electrodes for forming the storage capacitors70 through the dielectric films, the stacked type storage capacitors 70each consisting of the five layers including the first storage capacitorC1 to the fifth storage capacitor C5 can be formed. As a result, evenwith the regions, where the storage capacitors are formed, are narrow,the great storage capacitors 70 can be effectively formed. In the liquidcrystal device of this embodiment, at least the first storage capacitorsC1 may be formed. Even when, for example, the storage capacitorelectrodes 3 b cannot be formed because the aperture ratio anddefinition of the pixels are further increased, the structure of thisembodiment permits the formation of the sufficient storage capacitors 70by thinning the interlayer insulating film 91 as the dielectric film ofthe storage capacitors C1. Therefore, in this embodiment, any desiredstorage capacitor can be advantageously selected from the first storagecapacitors C1 to the fifth storage capacitors C5 and used according tothe specifications for the purpose of an electro-optical device.

[0160] Again refer to FIG. 3, the data lines 6 a are formed on theinterlayer insulating film 4 formed above the light-shielding conductivefilms 90 a. The data lines 6 a are also electrically connected to theheavily-doped source regions 1 d of the semiconductor layers 1 a throughthe contact holes 5 which are formed at the predetermined positions ofthe gate insulating films 2, the interlayer insulating film 81, theinterlayer insulating film 91, and the interlayer insulating film 4. Thedata lines 6 a consist of an Al metal film or metal silicide, or thelike having low resistance and high light-shielding property becauseimage signals are supplied thereto.

[0161] In the liquid crystal device of this embodiment, thelight-shielding regions as the non-aperture regions can be defined bythe data lines 6 a and the light-shielding conductive films 90 a. Morespecifically, as shown in FIG. 10, the light-shielding conductive films90 a are formed to overlap with the pixel electrodes 9 a so as to shieldthe most of the regions including the channel regions 1 a′. Also, themost of the regions along the data lines 6 a can be shielded by thelight-shielding conductive films 90 a, and unlike in a conventionaldisplay device, thus the light-shielding regions need not be definedonly by the data lines 6 a. Therefore, the data lines 6 a and the pixelelectrodes 9 a can be formed so as not to overlap with each other asmuch as possible through the interlayer insulating film 7. Therefore,the parasitic capacitors between the data lines 6 a and the pixelelectrodes 9 a can be significantly decreased, thereby preventing theoccurrence of deterioration in display image quality due to a change inpotential of the pixel electrodes 9 a. However, since thelight-shielding conductive films 90 a are formed below the data lines 6a, the regions where the contact holes 5 are formed for electricallyconnecting the data lines 6 a and the semiconductor layers 1 a cannot beshielded. Therefore, in the regions where the contact holes 5 areformed, the wide data lines 6 a may be formed so as to partially overlapwith the pixel electrodes 9 a. When the regions where the contact holes5 are formed is near the channel regions 1 a′, the vicinities of thechannel regions 1 a′ cannot be sufficiently shielded by thelight-shielding conductive films 90 a. In this case, the regions wherethe contact holes 5 are formed may be moved along the data lines 6 a inthe direction away from the channel regions 1 a′ without any problem.This embodiment has the advantage that even when the regions where thecontact holes 5 are formed are moved, the first storage capacitors C1formed between the relay films 80 a and the light-shielding conductivefilms 90 a are not changed. The light-shielding conductive films 90 acannot be provided in the regions where the contact holes 8 b are formedfor electrically connecting the relay films 80 a and the pixelelectrodes 9 a, and thus these regions may be shielded by the relayfilms 80 a. If the relay films 80 a consist of a light-transmissive filmsuch as a polysilicon film, the regions may be shielded by theunderlying light-shielding films 11 a. In this case, the regions wherethe contact holes 8 b are formed are preferably separated from thechannel regions 1 a′. As shown in FIG. 10, it is advantageous to formthe contact holes 8 b between the adjacent data lines 6 a so thatincident light does not reach the channel regions 1 a′ even when lightis incident on the underlying light-shielding films 11 a. Since thepixels can be formed in line symmetry with respect to the data lines 6a, for example, a projector including a combination of liquid crystaldevices including TN liquid crystals having different twistingdirections causes no deterioration in display image quality such ascolor irregularity.

[0162] In this way, in this embodiment, the light-shielding regions canbe defined on the TFT array substrate 10, and thus light-shielding filmsneed not be provided on the counter substrate 20, as shown in FIG. 3.Therefore, in mechanically combining the TFT array substrate 10 and thecounter substrate 20, even when alignment is shifted, the regions(aperture regions) where light is transmitted are not changed because nolight-shielding film is provided on the counter substrate 20. Therefore,a stable aperture ratio can be obtained to significantly decreasedefects in the device.

[0163] The liquid crystal device of this embodiment can also use astructure stronger against an angle of incident light than aconventional device. This will be described with reference to FIGS.11(A)-(B). FIG. 11(A) is a sectional view taken along line XI-XI′ inFIG. 2, and FIG. 11(B) shows a conventional structure. FIGS. 11(A) and(B) show the structures on same reduction scale.

[0164] In general, when light is incident on the vicinities of thechannel regions 1 a′ of the semiconductor layers 1 a, in an off state ofthe TFTs 30, the ability to hold the charges written on the pixelelectrodes 9 a are decreased by the occurrence of leakage currents dueto photo excitation. Therefore, this embodiment uses a structure inwhich the light-shielding conductive films 90 a are provided againstincident light L1, and the underlying light-shielding films 11 a areprovided against reflected light L2 so as to prevent light irradiationof the semiconductor layers 1 a, as shown in FIG. 11(A). Since thequality of reflected light L2 is one hundredth of the quality ofincident light L1, in the channel regions and the vicinities thereof,the width W1 of each of the light-shielding conductive films 90 a forshielding incident light L1 is larger than the width W2 of each of theunderlying light-shielding films 11 a. Namely, in the channel regionsand the vicinities thereof, the underlying light-shielding films 11 aare formed so as not to project from the light-shielding conductivefilms 90 a. Furthermore, in the channel regions and the vicinitiesthereof, the width W3 of each of the semiconductor layers 1 a is smallerthan the width W2 of each of the underlying light-shielding films 11 a.Namely, the channel regions and the vicinities thereof are covered withthe underlying light-shielding films 11 a, as viewed from the TFT arraysubstrate side. By using this structure, even when incident light L1 isincident at an angle, the probability that the incident light reachesthe semiconductor layers 1 a can be decreased. In this embodiment, sincethe light-shielding conductive films 90 a can be formed between the datalines 6 a and the semiconductor layers 1 a, light shielding can beachieved nearer to the channel regions than the conventional exampleshown in FIG. 11(B) in which the channel regions are shielded by thedata lines 6 a. In this embodiment and the conventional example,consideration is given to a margin for the incidence angle of theincident light L1. Since the semiconductor layers 1 a has a width W3 of,for example, as small as 1 μm, the incident light L1 is not likely to beincident directly on the semiconductor layers 1 a. Therefore, it isassumed that light incident on the underlying light-shielding films 11 aprovided below the semiconductor layers 1 a is reflected and incident onthe semiconductor layers 1 a. It is also assumed that the underlyinglight-shielding films 11 a of this embodiment shown in FIG. 11(A) andthe conventional example shown in FIG. 11(B) have the same width W2. Itis further assumed that the width W1 of each of the light-shieldingfilms 90 a for shielding the incident light L1 in this embodiment is thesame as the width W1 of each of the data lines 6 a in the conventionalexample. In this embodiment, the interlayer distance between theunderlying light-shielding films 11 a and the light-shielding conductivefilms 90 a is D1, while in the conventional example, the interlayerdistance between the underlying light-shielding films 11 a and the datalines 6 a is D2. Summing that the interlayer distance between theunderlying light-shielding films 11 a and the data lines 6 a in thisembodiment is D2, the relation D1>≦D2 is obtained. Therefore, when theincident light L1 is incident at the same angle, the margin for theangle of the incident light L1 in this embodiment is larger than that inthe conventional example by an amount corresponding to a decrease in theinterlayer distance to the underlying light-shielding films 11 a.Namely, assuming that the margin angle of the incident light L1 in thisembodiment is R1, and the margin angle of the incident light L1 in theconventional example is R2, the relation R1>R2 is obtained. As a result,the margin for the incidence angle of the incident light in the liquidcrystal device of this embodiment is larger than the conventionalexample, and thus the liquid crystal device of this embodiment canadvantageously comply with an increase in the incidence angle withminiaturization of an optical system. In this embodiment,light-shielding films can also be formed on the sides of thesemiconductor layers 1 a through insulating films to further improvecorrespondence to the incidence angle.

[0165] In the liquid crystal device of this embodiment, unlike in theconventional example, light shielding need not be attained by the datalines 6 a, and thus the width W4 of each of the data lines 6 a in thechannel region and the vicinities thereof can be made smaller than thewidth W1 of each of the light-shielding conductive films 90 a. Namely,the relation W1>W4 is obtained, and the data lines 6 a are thus formedso as not to project from the light-shielding conductive films 90 a inthe channel region and the vicinities thereof. Therefore, it is possibleto prevent the semiconductor layers 1 a from being irradiated with straylight reflected by the data lines 6 a. Particularly, since thelight-shielding conductive films 90 a can be formed by using a filmcontaining a high-melting-point metal having lower reflectance than Alwhich forms the data lines 6 a, stray light due to the data lines 6 acan also be absorbed by the light-shielding conductive films 90 a.

[0166] Furthermore, in the liquid crystal device of this embodiment, therelay films 80 a can be formed below the light-shielding conductivefilms 90 a, the vicinities of the semiconductor layers 1 a can beshielded by the relay films 80 a to improve the light-shieldingperformance. In this case, when the width of each of the relay films 80a is substantially the same as the width W1 of each of thelight-shielding conductive films 90 a, the light-shielding performancecan be further improved. If the reflected light L2 is incident from theTFT array substrate 10 side, in this embodiment, light is absorbed bythe relay films 80 a consisting of polysilicon films or low-resistancefilms containing a high-melting-point metal, while in the conventionalexample, stray light reflected below the data lines 6 a is likely to beincident on the semiconductor layers 1 a because the data lines 6 ahaving high reflectance are also used as light-shielding films. As aresult, stray light due to internal reflection can be significantlydecreased, thereby eliminating the need to take account of deteriorationin the display image quality due to a leakage of the TFTs 30. By formingthe relay films 80 a consisting of films with low reflectance, like thedata lines 6 a, the light-shielding conductive films 90 a may include afilm containing at least Al having high reflectance. Therefore, in thelight-shielding regions of the liquid crystal device, it is possible toform the data lines 6 a and the light-shielding conductive films 90 aconsisting of films containing at least Al having high reflectance of,for example, 80% or more in the visible region, and thus reflectincident light by the data lines 6 a and the light-shielding conductivefilms 90 a to prevent an increase in temperature of the liquid crystaldevice. In the liquid crystal device of this embodiment, for example, itis thus possible to decrease the cost required for developing a coolingdevice of a projector, and improve the light-shielding performance ofthe liquid crystal device.

[0167] In the above-described embodiment, the surface of the interlayerinsulating film 7 provided below the pixel electrodes 9 a is planarized.This is performed for preventing disclination of the liquid crystal dueto steps formed in wiring, elements, etc., and the lower interlayerinsulating film 4 may be also planarized. In this embodiment,planarization can be performed by coating an organic or inorganic SOG(Silicon On glass) film by a spin coater, or CMP process.

[0168] (Second Exemplary Embodiment)

[0169] The construction of an electro-optical device in accordance witha second embodiment of the present invention will be described belowwith reference to FIGS. 12 to 16.

[0170] In a liquid crystal device as an example of electro-opticaldevices, AC reverse driving must be generally performed for preventingdeterioration in a liquid crystal. Although several driving methods havebeen proposed, the liquid crystal of the second embodiment of thepresent invention uses a mechanism in which the polarities of imagesignals applied to the liquid crystal are reversed for each scanningline 3 a, and the polarities of the image signals are further reversedfor 1 field, as shown in FIG. 12. As a result, a DC component applied tothe liquid crystal can be suppressed as much as possible, and theoccurrence of flicker can be significantly decreased. When thepolarities of image signals applied to the liquid crystal are reversedfor each scanning line 3 a, the image signals having the same polarityare written in the pixel electrodes 9 a adjacent in the X directionalong the scanning lines 3 a, thereby producing no electric fieldbetween the adjacent pixel electrodes 9 a. On the other hand, the imagesignals having different polarities are written in the pixel electrodes9 a adjacent in the Y direction along the data lines 6 a, therebyproducing an electric field between the adjacent pixel electrodes 9 a tocause disclination 400 in the liquid crystal.

[0171] Therefore, in order to minimize the regions where thedisclination 400 occurs, as shown in FIG. 12, in the second embodimentof the present invention, grooves 10′ are formed in the shadowed regionsof a plurality of pixel groups on the TFT array substrate shown in FIG.13 so that wiring such as the data lines 6 a and the like, and TFTs 30are partially buried in the grooves to planarize the substrate. Inaddition, when the TFT array substrate is rubbed in the direction shownby arrows in FIG. 13, the grooves 10′ are not provided in the regions ofthe scanning lines 3 a, which is in contact with the aperture regions,to further decrease the regions where the disclination 400 occurs. As aresult, the regions of the pixels where light leaks, can be decreased,and the pixel aperture ratio can be significantly increased.Particularly, this embodiment is suitable for a liquid crystal devicefor a projector required to have brightness and a small size.

[0172]FIG. 14 is a sectional view taken along line XIV-XIV′ in FIG. 13.As shown in FIG. 14, the grooves 10′ are formed in the regions of theTFT array substrate 10 where the TFTs 30 and the storage capacitors 70are formed so that the pixel electrodes 9 a and the alignment film 16can be substantially flatly formed. The grooves 10′ can easily be formedby usual photolithography and etching. The taper angle of the sides ofthe grooves 10′ can be controlled to various angles by a dry etchingmethod or a wet etching method. In planarization by forming the grooves10′, control of the depth of the grooves 10′ is important, but the depthcan easily be controlled by controlling the dry etching time or thelike. In such planarization by forming the grooves 10′, planarizationcan be realized without using a photosensitive organic film or the like,and thus this method is particularly useful for a liquid crystal deviceof a projector using a strong light source.

[0173]FIG. 15 is a sectional view taken along line XV-XV′ in FIG. 13,showing the sectional structure between the pixel electrodes 9 aadjacent in the X direction shown in FIG. 12. In this way, the grooves10′ are formed in the TFT array substrate 10 to permit substantiallycomplete planarization of the regions where the data lines 6 a areformed. Particularly, in rubbing along the data lines 6 a, as shown inFIG. 13, no disclination occurs due to the steps formed by wiring suchas the data lines 6 a, and elements because the regions where the datalines 6 a, etc. are formed are buried in the grooves and planarized.

[0174]FIG. 16 is a sectional view taken along line XVI-XVI′ in FIG. 13,showing the sectional structure between the pixel electrodes 9 aadjacent in the Y direction shown in FIG. 12. Since disclination occursin the liquid crystal due to an electric field between the adjacentpixel electrodes 9 a, the grooves 10′ are not formed in the regions ofthe TFT array substrate 10 where the scanning lines 3 a are formed, soas to decrease the cell gap of the liquid crystal layer 50 in thepartition regions between the adjacent pixel electrodes 9 a, as shown inFIG. 16. Therefore, the electric field between the counter electrode 21provided on the counter substrate 20 and the pixel electrodes 9 a isincreased, and thus the regions where disclination occurs in the liquidcrystal can be decreased as much as possible even when an electric fieldoccurs between the adjacent pixel electrodes 9 a. Since the disclinationneed not be decreased by narrowing the cell gap of the liquid crystal,the problem of development of a liquid crystal for a narrow cell gap,the problem of causing difficulties in controlling the cell gap, etc. donot occur.

[0175] In this way, in the second embodiment of the present invention,the grooves 10′ are formed in the TFT array substrate 10 so that wiringand elements can be completely or partially buried therein, therebyrealizing an electro-optical device having a higher pixel apertureratio, as compared with a case such as the CMP process which can performonly complete planarization. When the grooves 10′ are formed not only inthe TFT array substrate 10 but also in the interlayer insulating filmsuch as the underlying insulating film 12 or the interlayer insulatingfilm 81, the same effect can be obtained. Of course, the grooves 10′provided in the TFT array substrate 10 may be combined with the groovesprovided in the interlayer insulating film such as the underlyinginsulating film 12 or the interlayer insulating film 81 forplanarization.

[0176] (Third Exemplary Embodiment)

[0177] The construction of a liquid crystal device as an electro-opticaldevice in accordance with a third embodiment of the present inventionwill be described with reference to FIGS. 17 and 18. FIG. 17 is a planview of a plurality of adjacent pixel groups on a TFT array substrate onwhich data lines, scanning lines, pixel electrodes, etc. are formed, andFIG. 18 is a sectional view taken along line XVIII-XVIII′ in FIG. 17. InFIG. 18, layers and members are shown on different reduction scales inorder to make each of the layers and the members recognizable in thedrawing.

[0178] As shown in FIG. 17, the third embodiment is greatly differentfrom the first embodiment in that auxiliary wirings 3 b′ also serving ascapacitor electrodes 3 b are formed by the same film as scanning lines 3a. The auxiliary wirings 3 b′ are extended from an image display regionto the periphery thereof along the direction of the scanning lines 3 aso as to be connected to a constant potential source in the peripheralregion. As the constant potential source, a constant potential sourcesuch as a negative power source, or a positive power source supplied toperipheral circuits for driving the liquid crystal device (for example,a scanning line driving circuit, a data line driving circuit), whichwill be described below, a ground power source, a constant potentialsource supplied to a counter electrode, or the like can be used. Theauxiliary wirings 3 b′ preferably have the same potential as thatsupplied to light-shielding conductive films 90 a. Therefore, theauxiliary wirings 3 b′ can be caused to function as parts of thecapacitor lines 300 shown in FIG. 1. Also, the auxiliary wirings 3 b′can be electrically connected to the upper light-shielding conductivefilms 90 a below data lines 6 a through contact holes 95. In this case,the auxiliary wirings 3 b′ may be connected to the light-shieldingconductive films 90 a through the contact holes 95 for each pixelelectrode 9 a or a plurality of the pixel electrodes 9 a. In this way,the capacitor lines 300 having a redundant structure can be formed bythe auxiliary wirings 3 b′ and the light-shielding conductive films 90a. Even when the first or second embodiment has a margin for thelight-shielding regions, of course, the capacitor electrodes 3 b may beextended to form the auxiliary wirings 3 b′.

[0179] The third embodiment is also greatly different from the firstembodiment in that relay films 80 a′ shown by slanted lines are formedso as not to overlap with the scanning lines 3 a in a plan view, asshown in FIG. 17. As a result, the interlayer insulating film 81 isformed to a thickness of 100 nm or less so that large storage capacitorscan be formed on the auxiliary wirings 3 b′ including capacitorelectrodes, as shown in FIG. 18. Namely, the storage capacitors C2 shownin FIG. 4 can be enlarged. In this case, since the interlayer insulatingfilm 81 for insulating the scanning lines 3 a and the relay films 80 a′is thinned, the relay films 80 a′ provided to overlap with the scanninglines 3 a enlarge parasitic capacitances, thereby delaying scanningsignals. Also, error occurs in the operation of the TFTs 30 due to theinfluence of a potential applied to the relay films 80 a′, and thus therelay films 80 a′ cannot be provided near channel regions 1 a′. However,the interlayer insulating film 81 between the semiconductor layers 1 aand the relay films 80 a′ can be greatly thinned, and thus nopenetration in the semiconductor layers 1 a occurs in forming contactholes 8 a for electrically connecting heavily-doped drain regions 1 e ofthe semiconductor layers 1 a and the relay films 80 a′. There is alsothe advantage that the aperture diameter of the contact holes 8 a can besignificantly decreased. Furthermore, in order that the channel regions1 a′, the vicinities thereof and the scanning lines 3 a are shielded bythe light-shielding conductive films 90 a, an interlayer insulating film91 must be formed to a thickness of 500 nm or more. However, the storagecapacitors C1 shown in FIG. 4 can be formed between the auxiliarywirings 3 b′ and the light-shielding conductive films 90 a.

[0180] (Fourth Exemplary Embodiment)

[0181] The construction of a liquid crystal device as an electro-opticaldevice in accordance with a fourth embodiment of the present inventionwill be described with reference to FIGS. 19 and 20. FIG. 19 is a planview of a plurality of adjacent pixel groups on a TFT array substrate onwhich data lines, scanning lines, pixel electrodes, etc. are formed, andFIG. 20 is a sectional view taken along line XX-XX′ in FIG. 19. In FIG.20, layers and members are shown on different reduction scales in orderto make each of the layers and the members recognizable in the drawing.The same members as the first embodiment are denoted by the samereference numerals, and description thereof is omitted.

[0182] In the fourth embodiment, as shown in FIG. 19, scanning lines 3 aand data lines 6 a are provided in substantially centers of non-apertureregions. Semiconductor layers 1 a are provided below the data lines 6 aso as to cross the scanning lines 3 a. As shown in FIG. 20, the datalines 6 a are electrically connected to heavily-doped source regions 1 dof the semiconductor layers 1 a below the data lines 6 a through contactholes 5. The heavily-doped drain regions 1 e of the semiconductor layers1 a are electrically connected to the relay films 80 a below the datalines through contact holes 8 a. In this way, the semiconductor layers 1a are arranged below the light-shielding data lines 6 a to exhibit theeffect of preventing direct incidence of light from the countersubstrate 20 side on the semiconductor layers 1 a. Furthermore, thesemiconductor layers 1 a and the contact holes 5 and 8 a are formed inline symmetry with respect to the center lines of the non-apertureregions in the direction of the scanning lines 3 a and the non-apertureregions in the direction of the data lines 6 a, thereby making the shapeof steps symmetric with respect to the data lines. This embodiment isthus advantageous because no difference occurs in light transmissionaccording to the rotation direction of the liquid crystal.

[0183] Furthermore, underlying light-shielding films 11 a are formedbelow the semiconductor layers 1 a with an underlying insulating film 12provided therebetween. The underlying light-shielding films 11 a areformed in a matrix along the direction of the data lines 6 a and thedirection of the scanning lines 3 a. The semiconductor layers 1 a arearranged inward of the underlying light-shielding films 11 a, therebycausing the effect of preventing direct incidence of light returned fromthe TFT array substrate 10 side on the semiconductor layers 1 a.

[0184] The relay films 80 a may consist of a polysilicon film, or aconductive film containing a high-melting-point metal or the like, andare extended in a substantially T shape along the scanning lines 3 a andthe data lines 6 a between the semiconductor layers 1 a and the pixelelectrodes 9 a so as to function as buffers for electrically connectingthe semiconductor layers 1 a and the pixel electrodes 9 a. Morespecifically, the heavily-doped drain regions 1 e of the semiconductorlayers 1 a are electrically connected to the conductive relay films 80 athrough the contract holes 8 a, and the relay films 80 a areelectrically connected to the pixel electrodes 9 a through the contactholes 8 b. In this structure, by providing the relay films 80 a having ahigh etching selection ratio, it is possible to avoid the possibility ofpenetration in the semiconductor layers 1 a during the formation of thecontact holes. In the contact holes 5 for electrically connecting thedata lines 6 a and the heavily-doped source regions 1 d of thesemiconductor layers 1 a, the same films as the relay films 80 a may beprovided for relay.

[0185] In the fourth embodiment, an interlayer insulating film 91 islaminated on the relay films 80 a, and the light-shielding conductivefilms 90 a are formed on the interlayer insulating film 91. Thelight-shielding conductive films 90 a are formed to cover the relayfilms 80 a except the contact holes 8 b. The light-shielding conductivefilms 90 a are also extended to the outside of the image display regionin the direction of the scanning lines 3 a so as to be electricallyconnected to any one of a constant potential source such as a negativepower source, a positive power source supplied to a scanning linedriving circuit, a data line driving circuit, etc., a ground powersource, a constant potential source supplied to a counter electrode, orthe like, thereby fixing the potential. Therefore, each of the relayfilms 80 a can be used as one of capacitor electrodes, and each of thelight-shielding conductive films 90 a can be used as the other capacitorelectrode to form each of the storage capacitors C1 shown in FIGS. 4 and5. In this embodiment, of course, the interlayer insulating film 91functions as a dielectric film. Since the interlayer insulating film 91is laminated only for forming the storage capacitors C1, the interlayerinsulating film 91 is thinned to a thickness which causes no leakagebetween the relay films 80 a and the light-shielding conductive films 90a, thereby increasing the storage capacitors C1. Furthermore, in thefourth embodiment, the relay films 80 a can be extended to portionsabove the TFTs 30 and the scanning lines 3 a by thickening theinterlayer insulating film 81, thereby efficiently increasing thestorage capacitors C1. Furthermore, in the fourth embodiment, thesemiconductor layers 1 a are not extended to form capacitor electrodes.Therefore, capacitor electrodes for forming the storage capacitors andcapacitor lines need not be formed by using the same film as thescanning lines 3 a, and thus the scanning lines 3 a can be formed at thesubstantially centers of the non-aperture regions defined by thelight-shielding conductive films 90 a and the underlying light-shieldingfilms 11 a, as shown in FIG. 19. Also, the semiconductor layers 1 aconsisting of a polysilicon film need not be decreased in resistance,and thus impurities need not implanted into the capacitor electrodeforming portions to decrease the number of steps.

[0186] In the fourth embodiment, the channel regions 1 a′ of the TFTs 30are respectively formed at the intersections of the scanning lines 3 aand the data lines 6 a so that the channel regions 1 a′ can be formed atthe substantially centers of the non-aperture regions in the directionof the data lines 6 a and the direction of the scanning lines 3 a. As aresult, the channel regions 1 a′ are located at positions which are mosthardly irradiated with light reflected by the counter substrate 20 sideand light returned from the TFT array substrate 10 side, therebysignificantly decreasing a leakage current of the TFTs 30 due to light.

[0187] Furthermore, in the fourth embodiment, as shown in FIG. 19, thelight-shielding conductive films 90 a, the relay films 80 a and theunderlying light-shielding films 11 a are formed near the channelregions 1 a′ so that the pattern width decreases in this order, toprevent direct incidence of light on the underlying light-shieldingfilms 11 a. Also, the relay films 80 a consisting of a polysilicon filmare interposed between the light-shielding conductive films 90 a and thesemiconductor layers 1 a to exhibit the effect of absorbing lightreflected by the surfaces of the underlying light-shielding films 11 aand light returned from the TFT array substrate 10 side. Therefore, thisembodiment is useful for light resistance.

[0188] Furthermore, in the fourth embodiment, the non-aperture regionsconsisting of the data lines 6 a, the light-shielding conductive films90 a, the underlying light-shielding films 11 a, etc. can be formed onthe TFT array substrate 10, whereby a light-shielding film need not beprovided on the counter substrate 20. Therefore, since nolight-shielding film is provided on the counter substrate 20, theregions (aperture regions) where light is transmitted is not changedeven when alignment is shifted in mechanically combining the TFT arraysubstrate 10 and the counter substrate 20. As a result, a stable pixelaperture ratio can be obtained, and defects of the device can besignificantly decreased.

[0189] (Whole Construction of Electro-Optical Device)

[0190] The whole construction of the liquid crystal device of each ofthe embodiments constructed as described above will be described withreference to FIGS. 21 and 22. FIG. 21 is a plan view showing the TFTarray substrate 10 together with components formed thereon, as viewedfrom the counter substrate 20 side, and FIG. 22 is a sectional viewtaken along line XXII-XXII′ in FIG. 21.

[0191] In FIG. 21, a sealing agent 52 is provided on the TFT arraysubstrate 10, on which elements and wiring are formed, along the edge ofthe counter substrate 20, and a light-shielding frame 53 is provided inparallel to the inner side of the sealing agent, for defining theperiphery of the image display region. The frame 53 may be provided onthe TFT array substrate 10 side, like in this embodiment, or the countersubstrate 20 side. In the region outside the sealing agent 52, a dataline driving circuit 101 for supplying an image signal to the data lines6 a with predetermined timing and external circuit connecting terminals102 are provided along one side of the TFT array substrate 10, and ascanning line driving circuit 104 is provided along each of the twosides adjacent to that side, for supplying a scanning signal to thescanning lines 3 a with predetermined timing. When a delay of thescanning signal supplied to the scanning lines 3 a is not a problem, ofcourse, the scanning line driving circuit 104 may be provided on oneside. Alternatively, the data line driving circuit 101 may be providedon both sides of the image display region along the sides thereof.Furthermore, a plurality of wirings 105 are provided on the remainingside of the TFT array substrate 10, for supplying a common signal to thescanning line driving circuits 104 provided on both sides of the imagedisplay region. Furthermore, a vertical conducting material 106 isprovided at least one of the corners of the counter substrate 20, forproviding electric conduction between the TFT array substrate 10 and thecounter substrate 20. Namely, the counter electrode potential appliedfrom the external circuit connecting terminals 102 is supplied to thecounter electrode 21 provided on the counter substrate 20 through thewiring provided on the TFT array substrate 10 and the verticalconducting materials 106. As shown in FIG. 22, the counter substrate 20is fixed to the TFT array substrate 10 with the sealing material 52.Besides the data line driving circuit 101 and the scanning line drivingcircuits 104, on the TFT array substrate 10 may be formed a samplingcircuit for supplying an image signal to the plurality of the data lines6 a with predetermined timing, a pre-charging circuit for supplying apredetermined voltage level pre-charge signal to the plurality of thedata lines 6 a before the image signal, an inspection circuit forinspecting quality, defects, etc. of the liquid crystal device in thecourse of manufacture, at the time of shipping, and the like. In theliquid crystal device of this embodiment, the peripheral circuits suchas the data line driving circuit 101, and the scanning line drivingcircuits 102 can be formed on the same TFT array substrate 10 in thestep of forming the TFTs 30 for controlling the pixel electrodes 9 a,thereby realizing a liquid crystal device having high definition andhigh density.

[0192] The TFT array substrate 10 may be electrically or mechanicallyconnected to driving LSI mounted on, for example, a TAB (Tape AutomatedBonding) substrate, through an anisotropic conductive film provided onthe peripheral portion of the TFT array substrate 10 instead ofproviding the data line driving circuit 101 and the scanning linedriving circuit 104 on the TFT array substrate 10. Furthermore, apolarizing film, a retardation film, a polarizer or the like may bearranged in the predetermined direction on each of the incident side ofthe counter substrate 20 and the outgoing side of the TFT arraysubstrate 10 according to the operation mode such as a TN mode, a VA(Vertically Aligned) mode, a PDLC (Polymer Dispersed Liquid Crystal)mode, or the like, and the normally black mode/normally white mode.

[0193] The liquid crystal device of each of the embodiments is used aseach of three light valves for R (red), G (green) and B (blue) in orderto apply to a color display projector, and light of each of the colorsseparated through a dichroic mirror for RGB color separation is incidenton each of the light valves. Therefore, in each of the embodiments, acolor filter is not provided on the counter substrate 20. However, a RGBcolor filter may be formed on the predetermined regions of the countersubstrate 20, which correspond to the pixel electrodes 9 a, togetherwith a protecting film therefore. Alternatively, a color filter layermay be formed by using a color resist or the like below the pixelregions 9 a on the TFT array substrate 10 corresponding to RGB. As aresult, besides the projector, the liquid crystal device of each of theembodiments can be applied to color display liquid crystal devices suchas direct-viewing type and reflection type color liquid crystaltelevisions. Furthermore, microlenses may be formed on the countersubstrate 20 in one-to-one correspondence with pixels. By forming themicrolenses, the converging efficiency of incident light can besignificantly improved to realize a bright liquid crystal device.Furthermore, an interference layer consisting of layers having differentrefractive indexes may be deposited on the counter substrate 20 to forma dichroic filter for creating RGB colors by using light interference.By using the counter substrate including the dichroic filter, a liquidcrystal device for brighter color display can be realized.

[0194] Although, in the liquid crystal device of each of theabove-mentioned embodiments, like in a conventional device, incidentlight is incident on the counter substrate 20 side, light may beincident on the TFT array substrate 10 side, and light may be emittedfrom the counter substrate 20 side because the underlyinglight-shielding films 11 a and the light-shielding conductive films 90 aare provided on the TFT array substrate 10. Also, a polarizer coatedwith an AR (Anti Reflection) film need not be provided on or an AR filmneed not be mounted on the back of the TFT array substrate 10 in orderto prevent reflection, thereby causing the advantage that the materialcost can be accordingly reduced, and the yield is not reduced due todust, flaws, etc. in mounting the polarizer. Furthermore, even when theefficiency of light utilization is improved by using a bright lightsource or polarization conversion with a polarization beam splitter,deterioration in image quality such as cross talk due to light does notoccur because of the excellent light resistance. Although, in each ofthe embodiments, the conductive films 90 a has the light shieldingability, the conductive films has no light shielding ability in somecases in which another light-shielding film is formed for light incidenton the counter substrate side. Even with the conductive films 90 ahaving no light shielding ability, the construction of each of theembodiments can enlarge the storage capacitors.

[0195] Furthermore, although a normal stagger type or coplanar typepolysilicon TFT is used as a switching element provided in each ofpixels, each of the embodiments is also effective for other types ofTFTs such as a reversed stagger type TFT, an amorphous silicon TFT.

[0196] An electro-optical device of the present invention is not limitedto the above-described embodiments, and appropriate modification can bemade within the gist and idea of the present invention which can be readfrom the claims and the entire specification. An electro-optical devicewith such modification is also included in the technical field of thepresent invention.

What is claimed is:
 1. An electro-optical device, comprising: a scanningline formed above a substrate; a data line crossing the scanning line; athin film transistor disposed in correspondence with an intersection ofthe scanning line and the data line; a pixel electrode electricallyconnected to a drain region of the thin film transistor; and a firststorage capacitor formed by a plurality of layers between a gateelectrode of the thin film transistor and the data line.
 2. Theelectro-optical device according to claim 1, the first storage capacitorincludes: a first capacitor electrode; an insulating film facing thefirst capacitor electrode; and a second capacitor electrode arrangedopposite to the first capacitor electrode with the insulating filmprovided therebetween to serve as a relay film for electricallyconnecting the drain region of the thin film transistor and the pixelelectrode.
 3. The electro-optical device according to claim 1, the firststorage capacitor is formed to overlap with each of a semiconductorlayer of the thin film transistor and the scanning line except aconnection region between a source region of the thin film transistorand the data line.
 4. The electro-optical device according to claim 2,further comprising: a second storage capacitor including: a secondcapacitor electrode; an insulating film facing the second capacitorelectrode; and a third capacitor electrode opposed to the secondcapacitor electrode with the insulating film provided therebetween andincluding a same film as the gate electrode.
 5. The electro-opticaldevice according to claim 4, the third capacitor electrode is formed inparallel with the scanning line except in the connection region betweenthe drain region of the thin film transistor and the second capacitorelectrode.
 6. The electro-optical device according to claim 4, the thirdcapacitor electrode is electrically connected to the first capacitorelectrode.
 7. The electro-optical device according to claim 6, theelectric connection between the third capacitor electrode and the firstcapacitor electrode is located in a region below the data line.
 8. Theelectro-optical device according to claim 4, the third capacitorelectrode comprises a part of a first capacitor lines extending alongthe scanning line, the first capacitor electrode includes a part of asecond capacitor line extending along the scanning line, and the firstand second capacitor lines are extended to the periphery of the imagedisplay region in which the pixel electrode is arranged, andelectrically connected to each other.
 9. The electro-optical deviceaccording to claim 4, further comprising: a third storage capacitorincluding: a third capacitor electrode; an insulating film facing thethird capacitor electrode; and a fourth capacitor electrode opposed tothe third capacitor electrode with the insulating film providedtherebetween and including a same film as the semiconductor layer. 10.The electro-optical device according to claim 9, the fourth capacitorelectrode is formed to extend from the drain region of the thin filmtransistor.
 11. The electro-optical device according to claim 9, thefourth capacitor electrode is formed in parallel with the scanning line.12. The electro-optical device according to claim 9, the capacity of thesecond storage capacitor is smaller than that of each of the firststorage capacitor and the third storage capacitor.
 13. Theelectro-optical device according to claim 4, further comprising: afourth storage capacitor including: the fourth capacitor electrodeincluding a same film as the semiconductor layer; an insulating filmfacing the fourth capacitor electrode; and a fifth capacitor electrodearranged opposite to the fourth capacitor electrode, with the insulatingfilm provided therebetween, for shielding the semiconductor layer fromlight.
 14. The electro-optical device according to claim 13, the fifthcapacitor electrode is electrically connected to the first capacitorelectrode in the periphery of the image display region.
 15. Theelectro-optical device according to claim 2, further comprising: a fifthstorage capacitor including: the first capacitor electrode; aninsulating film laminated on the first capacitor electrode; and a sixthcapacitor electrode arranged opposite to the first capacitor electrodewith the insulating film provided therebetween to form the pixelelectrode.
 16. The electro-optical device according to claim 15, thefifth storage capacitor is formed over the entire periphery of eachpixel.
 17. An electro-optical device, comprising: a scanning line formedabove a substrate; a data line formed above the substrate; a thin filmtransistor disposed in correspondence with an intersection of thescanning line and the data line; a pixel electrode electricallyconnected to a drain region of the thin film transistor; and a storagecapacitor having a first conductive film which forms at least onecapacitor electrode of the storage capacitor, and a second conductivelight-shielding film which forms another capacitor electrode and isarranged above a gate electrode of the thin film transistor, the secondlight-shielding conductive film electrically connecting a semiconductorlayer constituting the drain region to the pixel electrode, the secondconductive light-shielding film covers at least portions of a channelregion of the thin film transistor, a junction region between the sourceregion and the channel region of the thin film transistor, a junctionregion between the drain region and the channel region of the thin filmtransistor, and the source and drain regions adjacent to the respectivejunction regions.
 18. The electro-optical device according to claim 17,the first conductive film covers the channel region, and the data lineis formed on the channel region and the adjacent region thereof so asnot to project from the first conductive film in a plan view.
 19. Theelectro-optical device according to claim 17, each of the firstconductive film and the data line includes a film containing at leastAl.
 20. The electro-optical device according to claim 17, the firstconductive film is extended from the image display region in which thepixel electrode is arranged to the periphery thereof, and connected to aconstant potential source in the peripheral region.
 21. Anelectro-optical device, comprising: a scanning line formed above asubstrate; a data line formed above the substrate; a thin filmtransistor disposed in correspondence with an intersection of thescanning line and the data line; a pixel electrode electricallyconnected to a drain region of the thin film transistor; and a storagecapacitor having a first conductive film which forms at least onecapacitor electrode of the storage capacitor, and a second conductivelight-shielding film which forms another capacitor electrode and isarranged above a gate electrode of the thin film transistor, the secondlight-shielding conductive film electrically connecting a semiconductorlayer constituting the drain region to the pixel electrode; and achannel region of the thin film transistor covered with the data linearranged above the first conductive film with an insulating film formedtherebetween.
 22. An electro-optical device, comprising: a scanning lineformed above a substrate; a data line formed above the substrate; a thinfilm transistor disposed in correspondence with an intersection of thescanning line and the data line; a pixel electrode electricallyconnected to a drain region of the thin film transistor; a storagecapacitor having a first conductive film which forms at least onecapacitor electrode of the storage capacitor, and a second conductivefilm which forms another capacitor electrode and is arranged above agate electrode of thin film transistor, the second conductive filmelectrically connecting a semiconductor layer constituting the drainregion to the pixel electrode; and a third conductive film whichincludes a same film as the gate electrode, and which is arrangedopposite to the second conductive film with an interlayer insulatingfilm formed therebetween, the first conductive film and the thirdconductive film being electrically connected to each other by the firstconductive film and the third conductive film directly contacting eachother.
 23. The electro-optical device according to claim 22, the firstconductive film and the third conductive film being electricallyconnected to each other, and the second conductive film and a fourthconductive film being electrically connected to each other.
 24. Theelectro-optical device according to claim 22, the third conductive filmincludes a capacitor line which is extended from the image displayregion to the periphery thereof along the scanning line, and connectedto a constant potential source in the peripheral region, the firstconductive film being connected to the capacitor line.
 25. Theelectro-optical device according to claim 24, the underlyinglight-shielding film includes a light-shielding conductive film, and isconnected to the capacitor line of each pixel.
 26. An electro-opticaldevice, comprising: a scanning line formed above a substrate; a dataline formed above the substrate; a thin film transistor disposed incorrespondence with an intersection of the scanning line and the dataline; a pixel electrode electrically connected to a drain region of thethin film transistor; and a storage capacitor having a first conductivefilm which forms at least one capacitor electrode of the storagecapacitor, and a second conductive light-shielding film which formsanother capacitor electrode and is arranged above a gate electrode ofthe thin film transistor, the second light-shielding conductive filmelectrically connecting a semiconductor layer constituting the drainregion to the pixel electrode, the first conductive film includes a filmhaving a lower reflectance than the data line.
 27. The electro-opticaldevice according to claim 26, further comprising: an underlyinglight-shielding film which is arranged below the semiconductor layer onthe substrate and which is formed to cover at least the channel regionas viewed from the opposite side of the substrate, and not to projectfrom the first conductive film in a plan view of the channel region andthe adjacent region thereof.
 28. The electro-optical device according toclaim 27, at least either of the first conductive film and theunderlying light-shielding film is made of a high-melting-point metal.29. The electro-optical device according to claim 26, the firstconductive film has substantially the same size as the second conductivefilm under the data line.
 30. A projection display device, comprising:an electro-optical device including: a scanning line formed above asubstrate; a data line crossing the scanning line; a thin filmtransistor disposed in correspondence with an intersection of thescanning line and the data line; a pixel electrode electricallyconnected to a drain region of the thin film transistor; and a firststorage capacitor formed by a plurality of layers between a gateelectrode of the thin film transistor and the data line; and aprojection device that projects a light passing through theelectro-optical device.
 31. An electrode-optical device, comprising: ascanning line formed above a substrate; a data line formed above thesubstrate; a thin film transistor disposed in correspondence with anintersection of the scanning line and the data line; a pixel electrodeelectrically connected to a drain region of the thin film transistor;and a storage capacitor having a first conductive light-shielding filmwhich forms one of capacitor electrodes of the storage capacitor, isarranged below the pixel electrode, and a second conductive film whichforms another capacitor electrode, is arranged above a gate electrode ofthe thin film transistor and below the first conductive light-shieldingfilm, the second conductive film electrically connecting a semiconductorlayer constituting the drain region to the pixel electrode, the firstconductive light-shielding film and the second conductive film coveringat least portions of a channel region of the thin film transistor, afirst junction region between the source region and the channel regionof the thin film transistor, a second junction region between the drainregion and the channel region of the thin film transistor, the sourceand drain regions respectively adjacent to the first junction region andthe second junction region, a scanning line region and a data lineregion.